XaVSSsSSMI 


Spark  P/L/<p 
//?/<?/  fe/re 
Wafer  Space  — 


End  Sectional  View  of  Typical  Internal  Combustion  Motor.  The  Prime  Mover 
that  Made  the  Automobile,  Motorcycle,  Aeroplane,  and  Motor  Boat 
Possible. 


THE  MODERN 
GASOLINE  AUTOMOBILE 

ITS    DESIGN,    CONSTRUCTION 
MAINTENANCE   AND   REPAIR 


A    PRACTICAL,    COMPREHENSIVE    TREATISE 
DEFINING  ALL  PRINCIPLES  PERTAINING  TO 

GASOLINE    AUTOMOBILES    AND    THEIR 
COMPONENT   PARTS 

THE  MOST  COMPLETE  AND  UP-TO-DATE  EXPOSITION  ON 
GASOLINE  AUTOMOBILES   EVER   PUBLISHED 

INVALUABLE  TO  MOTORISTS,   STUDENTS,  MECHANICS.   REPAIR  MEN 

'  AUTOMOBILE   DRAUGHTSMEN,  DESIGNERS  AND  ENGINEERS 

EVERY  PHASE  OF  THE  SUBJECT  BEING  TREATED  IN 

A   PRACTICAL,   NON-TECHNICAL   MANNER 

I 

BY  VICTOR  W.   PAGE,  M.E. 

LATE  TECHNICAL   EDITOR   OF    "THE   AUTOMOBILE   JOURNAL" 


by  500  Specially  Made  Detailed  Illustrations  and  Diagrams 

THE    ILLUSTRATIONS    DEFINING    CONSTRUCTION    OF    PARTS    ARE    MADE    FROM 

ACCURATE    ENGINEERING    DRAWINGS    ACCORDING    TO    BEST 

AUTOMOBILE    ENGINEERING    PRACTICE 


NEW  YORK 

THE    NORMAN    W.    HENLEY   PUBLISHING  COMPANY 

132  NASSAU   STREET 

1912 


COPYRIGHTED,  1912,  BY 
THE   NORMAN   W.    HENLEY   PUBLISHING  COMPANY 

ALSO 

COPYRIGHTED    IN    ENGLAND    AND    ALL    OTHER    COUNTRIES 
WHICH  HAVE  BECOME  PARTIES  TO  THE  BERNE  CONVENTION 


All  rights  reserved 


FIRST  IMPRESSION 


ui  /his  book  have  been  specially  made  by  the 
publishers,  and  their  use  without  permission  is  strictly  prohibited 


COMPOSITION,    ELECTROTYPING    AND   PRESSWORK 
THE   TROW    PRESS,    NEW    YORK,  U.  S.  A. 


TO   MY   UNCLE 

ERNEST  F.  MCCARTHY 

A   PIONEER   AUTOMOBILE   DESIGNER  AND   CONSTRUCTOR 

THIS   TREATISE    IS   INSCRIBED 
IN   GRATEFUL   APPRECIATION.  OF   PRACTICAL   AID 

AND    MECHANICAL   INSTRUCTION 
GIVEN   AT  A  TIME   IT  WAS   MOST   NEEDED 


250472 


CONTENTS 


CHAPTER    I 

PAGES 

Defining  Trend  of  Modern  Practice — Explaining  Components  of  Motor 
Cars  and  Considering  Functions  of  Each  Group  of  Mechanism — 
Parts  of  Typical  Pleasure  Car  Chassis — Assembling  Typical  Chassis 
— Arrangement  of  Truck  Parts — Wind  Resistance  and  Body  De- 
sign— Classification  of  Motor-Car  Types 43-75 


CHAPTER   II 

How  Power  is  Generated — Forms  of  Power  Plants  Commonly  Used — 
Two-  and  Four-Cycle  Engine  Action — How  the  Gasoline  Engine 
Works — Internal  Combustion  Motor  Parts  and  Their  Functions — 
Typical  Single-Cylinder  Engines  Described — Sequence  of  Cycles  in 
One-  and  Two-Cylinder  Engines — Sequence  of  Cycles  with  Multiple- 
Cylinder  Engines — Actual  Duration  of  Strokes — Typical  Engine 
Types  Described — Features  of  Knight  Slide-Valve  Motor — Action  of 
Poppet  Valve  Motor  Described — Operating  Principles  of  Two-Cycle 
Engines — Two-Port  Two-Cycle  Motor  Action — How  Three-Port  Two- 
Cycle  Engine  Operates — Action  of  Differential  Piston  Two-Cycle 
Motor — Why  Two-Cycle  Motor  is  Not  Widely  Used  in  Automobiles 
— Power-Plant  Installation — Three-Point  Support — Unit  Power- 
Plant  Advantages 76-118 


CHAPTER    III 

The  Principal  Parts  of  Gasoline  Engines,  their  Design,  Construction, 
and  Application — Methods  of  Cylinder  Construction — Influence  of 
Crankshaft  Design — Combustion-Chamber  Design — Bore  and  Stroke 
Ratio — Meaning  of  Piston  Speed — Advantages  of  Offset  Cylinders 
— Influence  of  Cylinder  Construction  on  Engine  Design — Valve  Lo- 
cation of  Vital  Import — Separable  Head  Motors — Valve  Design  and 
Construction — Valve  Operation  Means — Methods  of  Driving  Cam- 
shaft— Spur  Camshaft  Gearing — Silent  Chain  Camshaft  Drive — 
Valve  Springs — Piston  and  Rotary  Valve  Motors — The  Valveless 
Miesse  Engine — The  Itala  Rotary  Valve  Motor — The  Reynolds  Ro- 
tary Valve  Design — Cylindrical  and  Conical  Rotary  Valves — The 

3 


4  Contents 

*-  *<  ..    *  *    .    V  -   .  .  PAGES 

Sphinx  Ring:Valve  Motor — Darracq  Rotary  Distributor  Valve — The 
Hewitt  Piston-Valve  Motor — Valve  Timing — Causes  of  Blowing 
Back — Lead  Given  Exhaust  Valve — Exhaust  Closing,  Inlet  Open- 
ing— Closing  the  Inlet  Valve — Time  of  Ignition — Typical  Valve- 
Timing  Diagrams  Outlined  . 119-185 

CHAPTER    IV 

Constructional  Details  of  Pistons — Methods  of  Wristpin  Retention — Pis- 
ton-Ring Construction — Connecting-Rod  Forms — Camshaft  Forms 
—Crankshaft  Types  Outlined — Typical  Built-up  Crankshaft — Two- 
Cylinder  Crankshaft — Types  for  Four-  and  Six-Cylinder  Engines— 
Bali-Bearing  Crankshafts — Flywheel  Construction  and  Retention 
Utility  of  Fan-Blade-Form  Spokes — Marking  Flywheel  Rim  to 
Indicate  Valve  Timing — Engine-Base  Construction  Outlined — Barrel 
Type  Crankcase — Divided  Crankcases — Typical  Two-Cycle  Motors 
— The  Amplex  Power  Plant — The  Legros  Design — Features  of  Cote 
Differential  Piston  Motor — The  Rayner  Construction — Conventional 
Four-Cycle  Power  Plants  .  . 186-230 

CHAPTER    V 

Denning  Liquid  Fuels  Used  and  Methods  of  Vaporizing  to  Obtain  Ex- 
plosive Gas — Distillates  of  Crude  Petroleum — Benzol  and  Its  Prop- 
erties— Special  Vaporizers  Needed  for  Kerosene — Advantages  of  Al- 
cohol— Solid  Gasoline  as  Fuel — Principles  of  Carburetion  Outlined 
— What  a  Carburetor  Should  Do — Methods  of  Carrying  Fuels  in 
Automobiles — Gravity-Feed  Systems — Gasoline  Supply  by  Pressure 
— Fuel  Supply  by  Pump — Early  Vaporizer  Forms — Wick  Carbu- 
retor Construction — Filtering  or  Bubbling  Vaporizers — Marine 
Type  Mixing  Valves — Development  of  Float-Feed  Carburetor — 
Elements  of  Carburetor  Design — Mixing  Chamber  Forms — Problem 
of  Float-Bowl  Design — Gasoline  Spray  Nozzle  Forms  Important — 
Typical  Auxiliary  Air  Valves — Methods  of  Gas-Supply  Regulation 
— Use  of  Automatic  Governor — Construction  of  Modern  Carbu- 
retors— Schebler  Models — Kingston  Carburetor — Holley  Carburetor 
Features — Features  of  Mercedes  Carburetor — Chapin  Carburetor  De- 
sign— Excelsior  Carburetor  Construction — Pierce-Arrow  Vaporizer 
— Grouvelle  and  Arquemburg  Mixing  Device — Peerless  Carburetor 
and  Induction  Manifold — Breeze  Automatic  Carburetor  Features — 
Multiple-Nozzle  Carburetors — Stromberg  Double-Jet  Device — Car- 
buretor Used  on  F.  I.  A.  T.  Motor — Saurer  Economy  Carburetor — 
The  Zenith  Appliance — Utility  of  Gasoline  Strainers — How  Kero- 
sene May  Be  Utilized — Holley  Kerosene  Vaporizer — Supplying 


Contents  5 

PAGES 

Kerosene  by  Direct  Injection — Intake  Manifold  Design  and  Con- 
struction— Compensating  for  Varying  Atmospheric  Conditions — 
Disposition  of  Exhaust  Gases — Muffler  Forms — Utility  of  Cut- Out 
Valve 231-306 

CHAPTER    VI 

Automobile  Power-Plant  Ignition  Systems  Outlined — Chemical  Current 
Production — How  Primary  Cells  are  Used — Construction  of  Dry 
Battery — Methods  of  Coupling  Dry  Cells — Principles  of  Storage- 
Battery  Construction — Dynamo  Electric  Machines — Typical  Gov- 
erned Dynamo — Ford  Magneto  Generator  Distinctive — Timer  and 
Distributor  Forms — Arrangement  of  'JiHiier  Contacts — Essential  Ele- 
ments of  S^Hrple  Ignition  System — Induction-Coil  Forms — Spark- 
Plug  De^ig*n  and  Application — Plugs  for  Two-Spark  Ignition — 
Typical  Battfcrf  Ignition  Systems — Features  of  Low-Tension  Igni- 
tion— Make  and  Break  Igniter  Plate — Magneto-Generator  Construc- 
tion— High-Tensi^r^Magneto  Systems — Inductor  M^giie'to  Design — 
Installation  and  Drive  of  Magnetos — Double-Ignition  System  .  307-367 

CHAPTER    VII 

. 

Reason  for  Lubrication  of  Mechanism — Theory  of  Lubrication — Deriva- 
tion of  Lubricants — Devices  for  Supplying  Oil — Gravity  Feed  Oil- 
ers— Mechanical  Oiling  Methods — Oil  Supply  by  Constant  Level 
Splash  System — Distributing  Lubricant  by  Pressure — Individual 
Pump  System — Why  Cooling  Systems  are  Necessary — Cooling  Sys- 
tems Generally  Applied — Cooling  by  Positive  Water  Circulation — 
Forms  of  Water  Pumps — Water  Circulation  by  Natural  System — 
Direct  Air-Cooling  Methods — Utility  of  Auxiliary  Exhaust  Valves 
— Forms  of  Air  Fans — Two-Cycle  Air-Cooled  Engine — The  Frank- 
lin Air-Cooling  System — The  Frayer-Miller  Blower  System  .  368-405 


CHAPTER    VIII 

Utility  of  Clutches  and  Gearsets  Defined— Why  These  are  Needed  on  All 
Gasoline-Motor-Driven  Vehicles — Clutch  Forms  and  Their  Require- 
ments— How  Friction  Clutches  Transmit  Power — Materials  Em- 
ployed to  Increase  Frictional  Adhesion — Forms  of  Cone  Clutches 
Outlined — Attaching  Leather  Facings  to  Cones — Securing  Gradual 
Engagement — Three-  and  Five-Plate  Clutches — Features  of  Multi- 
ple-Disk Clutches — Functions  of  Gearsets — Face-Friction  Gearing — 
Installing  Face-Friction  Gears — How  Planetary  Gearing  Operates — 


6  Contents 

PAGES 

Typical  Planetary  Gearsets — Form  Using  Internal  Gears — All  Spur 
Epicyclic  Gearing — Individual  Clutch  Transmission — Silent  Chain 
Transmission — How  Sliding  Gearsets  Operate — Action  of  Progres- 
sive System — Operation  of  Selective  Sliding  Gearset — Typical 
Three-  and  Four-Speed  Sliding  Gearsets — Methods  of  Installing 
Change  Speed  Gearing  in  Chassis — Combination  with  Power  Plant 
Unit — Rear  Axle  Transmission  Gear  Combination  .  406-459 


CHAPTER    IX 

The  Chassis  and  Its  Components — Frame  Design  and  Construction — Ad- 
vantages of  Low  Weight  Placing — Underslung  Frame  Type — Ma- 
terials Employed  in  Frame  Construction — Suspension  of  Motor 
Vehicles — Design  of  Leaf  Springs — Suspending  Front  Ends  of  Motor- 
Car  Frames — Rear  End  Suspension — Unconventional  Spring  Forms 
— How  Automobiles  are  Steered — Features  of  Pivoted  Axle — Rack 
and  Pinion  Steering  Gear — Worm  Gear  Reduction  Steering  Device 
— Thread  and  Nut  Steering  Arrangement — Spark  and  Throttle 
Lever  Location — Front  Axle  Forms — I  Beam  Axle — Tubular  Axle 
Construction — Steering  Knuckle  Design — Methods  of  Power  Trans- 
mission— Straight  Line  Shaft  Drive — Rear  Axle  Types — Live  and 
Stationary  Axle  Combination — Purpose  of  Differential  Gear — Bevel 
Gear  Drive  Assembly — Worm  Gear  Driving — Axles  Employing  Dou- 
ble Reduction  Gearing — Chain  Driving  Method — Utility  of  Motor- 
Car  Brakes — Forms  of  Brakes — Internal  and  External  Band  Brakes 
—Multiple-Disk  Brake— Application  of  Front  Wheel  Brakes  .  460-508 


CHAPTER    X 

Wheels,  Rims  and  Tires— Characteristics  of  Wooden  Wheels — Wire  and 
Metal  Wheels — Spring  and  Resilient  Wheels — Forms  of  Automobile 
Tires — Construction  of  Pneumatic  Tires — Clincher  Type — Dunlop 
Type  Outer  Casing — Quick  Detachable  Rim  Forms — Fisk  Bolted-On 
Casing — Forms  of  Outer  Casing  Treads — Supplementary  Treads 
and  Anti-Skidding  Attachments — Demountable  Rim  Forms — Fea- 
tures of  Cushion  Tires — Sectional  Cushion  Tires — Forms  of  Solid 
Rubber  Tires — Methods  of  Fastening  Solid  Tires — Twin  Type  Solid 
Tires — Tools  and  Supplies  for  Pneumatic  Tire  Restoration — Tire 
Irons  and  Their  Use — Small  Repair  Kit  for  Emergency  Repairs — 
Tire  Manipulation  Hints — Loosening  Clincher  Casings  from  Rim  of 
Wheel — Tools  for  Removing  Bolted-On  Casings — Rules  for  Tire 
Selection  and  Inflation — Increase  in  Air  Pressure  Caused  by  Driv- 
ing— Tire  Repair  and  Maintenance — Some  Conditions  That  Cause 


Contents  7 

PAGES 

Tire  Failure — Repairing  Punctures — Restoring  Outer  Casing  That 
Has  "  Blown  Out " — Small  Vulcanizers  and  Their  Use — Replacing 
Inner  Tubes  509-559 

CHAPTER   XI 

Motor  Car  Equipment  and  Accessories — Self-Starters  for  Gasoline  En- 
gines— Ignition  Starters — Gas  Starting  Systems — Compressed  Air 
Starting  Methods — Starting  the  Gasoline  Engine  by  Electric  Motor 
— Motor  Car  Lighting  Systems — Acetylene  Gas  Lighting  Systems 
— Method  of  Generating  Gas — Action  of  Automatic  Gener- 
ator— Electric  Lighting  Systems — Special  Lighting  Battery — 
Forms  of  Electric  Lamps — Combination  Kerosene  and  Electric 
Lamps — Incandescent  Bulbs  and  Sockets — Special  Electric  Light- 
ing Fixtures — Construction  of  Electric  Headlight — Combination 
Gas  and  Electric  Headlights — Typical  Three-Lamp  Lighting 
System — Complete  Six-Lamp  Three-Circuit  Lighting  System 
— Utility  of  Windshields — Windshield  Construction — Functions 
of  Shock  Absorbers — Auxiliary  Springs — Dampening  Spring  Ac- 
tion— Motor  Car  Warning  Signals — Speed  Measuring  Devices — 
Tools  and  Miscellaneous  Equipment — Small  Tool  Outfit  Outlined 
— Supplementary  Useful  Tools — General  Supplies  and  Spare  Parts 
— Car-Raising  Jacks — How  Supplies  May  Be  Carried  .  .  560-606 

CHAPTER    XII 

Operating  Advice  and  Explanation  of  Automobile  Control  Methods — How 
to  Start  a  Gasoline  Engine — How  Motor  Speed  is  Controlled — Ma- 
nipulation of  Spark  Lever — Why  Spark  Lever  is  Advanced  and 
Retarded — Position  of  Sp#rk  and  Throttle  Control  Levers  to  Obtain 
Varying  Speeds — Controlling  Cars  with  Friction  Transmission — 
Obtaining  Varying  Speed  Ratios  with  Planetary  Gearsets — How  to 
Run  a  Maxwell  Car — Operating  Ford  Model  vT — Gear  Selection 
of  Brush  Runabout — Operating  Sliding  Gearsets — How  Selective 
Gears  are  Shifted — Typical  Change  Speed  Gates — Left-Hand  Con- 
trol— Typical  Speed-Changing  Systems — General  Driving  Instruc- 
tions— Suggestions  for  Oiling — Winter  Care  of  Automobiles — Anti- 
Freezing  Solutions — Spot-Removing  Preparations  ...  .  607-640 

CHAPTER    XIII 

Practical  Hints  to  Assist  in  Locating  Power-Plant  Troubles — Systematic 
Detection  of  Conditions  to  which  Imperfect  Engine  Operation  Can 


8  Contents 

PAGES 

Be  Ascribed — Faults  of  Ignition  System — Derangements  of  the  Car- 
buretor Group  and  Their  Symptoms — Cooling  and  Lubrication 
Group  Troubles 641-652 

CHAPTER    XIV 

Keeping  Up  the  Motor-Car  Chassis — Common  Defects  of  Clutches  and 
Gearsets — Faults  in  Chain-  and  Shaft-Driving  Systems — Troubles  in 
Front  and  Rear  Axles — Adjustment  of  Brakes — Care  of  Miscella- 
neous Chassis  Components — Maintenance  of  Body  Finish,  Tops  and 
Upholstery 653-667 

INDEX  669 


LIST   OF   ILLUSTRATIONS 

CHAPTER    I 

PAGE 

Fig.  1. — Plan  View  and  Side  Elevation  of  Pleasure  Car  Chassis  Propelled 
by  Four-Cylinder  Gasoline  Motor  Showing  Important  Components 
and  their  Relation  to  Each  Other  in  the  Assembly  ....  46-47 

Fig.  2. — Plan  View  Depicting  Important  Parts  of  a  Prominent  English 
Pleasure  Car  Chassis  in  which  Power  is  Furnished  by  a  Six-Cylinder 
Internal  Combustion  Engine 48-49 

Fig.  3.— Side  Elevation  of  Sheffield-Simplex  Six-Cylinder  Chassis;  a 

Typical  Design  of  English  Derivation 50 

Fig.  4. — Plan  and  Side  Elevation  of  Heavy  Commercial  Truck  Chassis  of 
Foreign  Design  showing  Essential  Elements  and  their  Location  in 
the  Frame 50-51 

Fig.  5. — Plan  View  of  Light  American  Motor  Truck  Chassis       .        .  52 

Fig.  6. — Side  Elevation  of  Light  Truck  Chassis  Showing  Important 

Mechanism 53 

Fig.  7. — Front  View  of  Gasoline  Pleasure  Car  Chassis  with  Section  of 

Radiator  Broken  Away  to  Show  Placing  of  Power  Plant  in  Frame  54 

Fig.  8. — Showing  Typical  Pressed  Steel  Frame  which  Forms  the  Founda- 
tion of  the  Modern  Gasoline  Automobile  before  Placing  Parts  of 
the  Mechanism 55 

Fig.  9. — Views  Detailing  Further  Steps  in  Assembling  Typical  Gasoline 

Car  Chassis  Illustrating  Location  of  Motor  and  Gear  Box  .  .  56 

Fig.  10. — How  the  Pleasure  Car  Chassis  Looks  with  Rear  Axle  Installed 

and  Gearset  Coupled  to  Engine 57 

Fig.  11. — After  Driving  Shaft,  Steering  Wheel  and  Control  Levers  are 

Added  the  Chassis  Begins  to  Assume  a  Finished  Appearance  .  59 

Fig.  12. — Plan  View  of  Chassis  when  Radiator,  Cooling  Fan  and  Muffler 

Have  Been  Put  in  their  Proper  Places 59 

Fig.  13. — The  Finished  Chassis  as  it  Appears  After  the  Front  Wheels, 
Tires,  Traction  Wheels,  Brake  Drums,  Running  Boards  and  Finish- 
ing Touches  Have  Been  Made .  60 

Fig.  14. — Front  View  of  Typical  Gasoline  Car  of  Modern  Design  Showing 
Parts  which  Tend  to  Impede  Speed  of  Car  by  Producing  Air  Resist- 
ance .  .  .  .  .  .  . 63 

Fig.  15. — Side  View  of  Typical  Gasoline  Car  Demonstrating  Influence  of 

Body  Form  on  Air  Flow 64 

9 


10  List  of  Illustrations 

PAGE 

Fig.  16. — Plan  View  Showing  Path  of  Air  Currents  Around  Body. of 
Gasoline  Car  when  No  Attempt  Has  Been  Made  to  Secure  Lessened 
Air  Resistance 65 

Fig.  17. — Depicting  Flow  of  Air  Currents  Around  Torpedo  Body  Designed 

to  Reduce  Friction  of  Atmosphere  at  High  Speeds  ...  66 

Fig.  18. — Plan  View  of  Vehicle  Body  Shown  in  Preceding  Illustration 
which  Clearly  Indicates  Influence  of  Symmetrical  Body  Form  in 
Promoting  Lessened  Air  Resistance 66 

Fig.  19. — Outline  of  Exaggerated  Torpedo  Body  -Type,  Seldom  Seen  Ex- 
cept on  Racing  Cars 67 

Fig.  20. — Typical  Modern  Roadster  Chassis  Fitted  with  Fore  Door  Body, 

Showing  Application  of  Stream  Line  Body  Form  in  Practice  .  67 

Fig.  21. — Application  of  Fore  Door,  Five-Passenger  Touring  Body  to 

Gasoline  Car  Chassis 68 

Fig.  22. — The  Coupe;  a  Popular  Form  of  Closed  Body  Favored  by  Pro- 
fessional Men  08 

Fig.  23. — The  Rockwell  Taxicab,  or  Public  Service  Vehicle,  with  Con- 
vertible Type  Body,  which  May  Be  Used  as  Shown  and  which  Be- 
comes a  Closed  Car  when  the  Top  is  Raised 69 

Fig.  24. — One  and  one-half  Ton  Capacity  White  Truck;  a  Conventional 
Example  of  American  Commercial  Car  Having  Power  Plant  Located 
Under  the  Hood,  as  in  Pleasure  Car  Practice 70 

Fig.  25. — Front  and  Rear  Elevation  of  Special  Sampson  Truck,  Designed 

for  United  States  Army  Service 71 

Fig.  26. — Side  View  of  Sampson  Army  Type  Transport  Wagon     .        .  71 

Fig.  27. — Showing  Typical  American  Motor  Truck  Design  in  which 
Power  Plant  is- Placed  Under  Operator's  Feet,  thus  Providing  More 
Carrying  Space  for  Body  without  Lengthening  Wheel  Base  .  72 

Fig.  28. — Motor  Truck  Chassis  Fitted  with  Special  Body  for  Fire  Depart- 
ment Service;  a  New  Field  to  which  the  Gasoline  Motor  is  Par- 
ticularly Well  Adapted .  .  72 

Fig.  29. — Showing  Different  Body  Forms  Fitted  to  Same  Chassis  Type  73 

Fig.  30. — Light  Motor  Truck  Chassis  which  Follows  Typical  Pleasure 
Vehicle  Design  Except  in  Size  of  Parts.  The  Frame  and  Running 
Gear  are  Heavier  and  Stronger,  to  Compensate  for  the  Greater 
Load-Carrying  Capacity  .  74 

CHAPTER  II 

Fig.  31. — Typical  Motor  Car  Power  Plant  Showing  External  Appearance 

and  Location  of  Important  Auxiliary  Mechanisms  ....  77 

Fig.  32. — Diagram  Comparing  Action  of  -Four-Cycle  Engine  with  that  of 
Muzzle -Loading  Cannon  in  Order  to  Simplify  Explanation  of  Cycle 
of  Operations,  thus  Enabling  the  Reader  to  Comprehend  this  Funda- 
mental Principle  Clearly 78-79 


List  of  Illustrations  11 

PAGE 

Fig.  33. — Sectional  View  One-Cylinder  Horizontal  Engine  Used  on  Some 
Reo  Models,  a  Type  that  is  Rapidly  being  Replaced  by  Four-Cylinder 
Motors.  These  Motors  were  Operated  at  Moderate  Speed  and  Had 
Considerable  Vibration  if  Speeded  Up  or  Run  Slowly  ...  83 

Fig.  34. — Sectional  View  of  Brush  Runabout  Motor,  a  Simple  Single- 
Cylinder  Power  Plant  of  the  Vertical  Type,  Designed  to  Operate  at 
High  Speeds 85 

Fig.  35. — Diagrams  Illustrating  Sequence  of  Cycles  in  One-  and  Two- 
Cylinder  Engines  Show  More  Uniform  Turning  Effort  on  Crank- 
shaft with  Two-Cylinder  Motors 86 

Fig.  36. — Diagrams  Demonstrating  Clearly  Advantages  which  Obtain 
when  Multiple-Cylinder  Motors  are  Used  as  Power  Plants.  The 
Continuous  Power  Application  Possible  Makes  for  Even  Turning 
Movement  and  Reduces  Vibration 89 

Fig.  37. — Diagram  Showing  Actual  Duration  of  Different  Strokes  in 

Degrees • 92 

Fig.  38. — Simple  Form  of  Two-Cylinder  Motor  Having  Opposed  Cylin- 
ders; a  Very  Popular  Form  of  Power  Plant  for  Light  Service  .  93 

Fig.  39. — Sectional  View  of  Four-Cylinder  Motor,  the  Most  Widely  Used 

Type  of  Multiple  Cylinder  Engine  .  94 

Fig.  40. — Sectional  View  of  Typical  Four-Cycle,  Four-Cylinder  Engine 
Showing  Important  Internal  Components  and  their  Relation  to  Each 
Other * •  .  .  '  .  .  ...  95 

Fig.  41. — Sectional  View  of  Rear  Cylinder  of  Gasoline  Engine  with  Im- 
portant Parts  Indicated 96 

Fig.  42. — Comparing  Poppet  Valve  and  Sliding  Sleeve  Valve  Power 
Plants.  Upper  View  Shows  Knight  Engine  with  Sleeves  to  Control 
Gas  Ports.  Lower  Illustration  Shows  Gas  Passages  Controlled  by 
Mushroom  Valves 98 

Fig.  43. — Showing  Action  of  Inlet  Valve  and  Cam  of  Conventional  Type. 
Note  Gradual  Valve  Opening,  which  Does  Not  Attain  its  Full  Value 
for  Some  Time 100 

Fig.  44. — Showing  Action  of  Exhaust  Valve  of  Conventional  Motor  Type     102 

Fig.  45. — End  Sectional  View  of  Knight  Sliding  Sleeve  Type  Motor 
Showing  Sleeves  which  Take  Place  of  the  Poppet  Valves  of  Conven- 
tional Motors.  A— Outer  Valve  Shell.  B— Inner  Valve  Shell.  C— 
Operating  Lever  for  A.  D — Operating  Lever  for  B.  E — Lay  Shaft, 
F — Crank  Shaft.  G— Helical  Gears.  H— Valve  Opening,  K — Cyl- 
inder Head.  L — Sparking  Plug  Holes.  0 — Cross-shaft  Driving 
Pump  and  Magneto.  U — Piston 103 

Fig.  46. — Diagrams  Depicting  Action  of  Sliding  Sleeves  on  Intake  Stroke. 
A — Inlet  Port  About  to  Open.  B — Inlet  Port  Fully  Open.  C — Inlet 
Port  Closed  104-105 


12  List  of  Illustrations 


PAGE 


Fig.  47. — Diagrams  Illustrating  Movement  of  Sliding  Sleeve  Valves  on 
the  Exhaust  Stroke.  A — Exhaust  Port  About  to  Open.  B — Exhaust 
Port  Fully  Open.  C — Exhaust  Port  Closed  ....  104-105 

Fig.  48. — Defining  Two-Port,  Two-Cycle  Engine  Action   ....          107 

Fig.  49. — Showing  Three-Port,  Two-Cycle  Engine  Operation   .        .        .          109 

Fig.  50. — Explaining  Action  of  Differential  Piston  Type  of  Two-Cycle 

Engine Ill 

Fig.  51. — Denning  Advantages  of  Unit  Power  Plant  Construction  when 

Supported  on  Three  Points 114 

Fig.  52. — Four-Cylinder  Power  Plant  and  Transmission  Unit  Adapted  for 

Three-Point  Support 115 

Fig.  53. — Six-Cylinder  Unit  Power  Plant  Utilized  in  Knox  Motor  Car  is 

Supported  by  Four  Points 115 

Fig.  54. — Views  of  Typical  Power  Plant  as  Installed  in  Motor  Car  Frame, 

the  Common  Method  of  Installation  in  Pleasure  Cars  .  .  116 

Fig.  55. — Showing  Method  of  Installing  Engine  in  Light  Truck.  Seat 
and  Dashboard  Units  Removed  to  Illustrate  Accessibility  of  Engine 
if  Extensive  Repairs  are  Necessary 118 

CHAPTER    III 

Fig.  56. — Illustrating  Different  Methods  of  Cylinder  Construction  Com- 
monly Employed.  A — Single  or  One-Cylinder  Casting  Used  on  Jack- 
son Cars.  B — Individual  Cylinder  Forming  Part  of  Knox  Power 
Plant.  C — Typical  Twin  Casting  Generally  Used  on  Motor  Car 
Engines.  D — Four  Cylinders  Cast  in  One  Block,  a  Feature  of  the 
Chalmers  "30"  Motor  .120 

Fig.  57. — Block  Casting  of  Everitt  "  Six,"  a  Remarkable  Innovation  in 
Motor  Design  Because  the  Six  Cylinders,  Upper  Part  of  Crank  Case 
and  Inlet  and  Exhaust  Manifolds  are  Included  in  One  Casting  .  122 

Fig.  58. — Example  of  Four-Cylinder  Block  Motor  Having  One  Separately 
Cast  Head  Member  Common  to  All  Cylinders.  A  Copper-Asbestos 
Gasket  is  Utilized  in  Making  a  Gas  and  Water  Tight  Joint  Between 
the  Parts.  Note  Accessibility  of  Pistons  and  Valves  .  .  .  123 

Fig.  59. — Showing  Separable  Head  Construction  of  Argyl  Sleeve  Valve 

Motor,  Made  Necessary  by  Use  of  Sleeve  .  .  .  .  .  ."  ;  125 

Fig.  60. — Section  Through  Sheffield  Simplex  (English)  Engine,  Presented 
to  Show  Excellent  Proportions  of  Water-jacket  Spaces  and  Easy 
Gas  Passages  Leading  to  Valve  Chest 127 

Fig.  61. — Section  Through  Sizaire-Naudin  (French)  Motor  Showing  a 

Typical  Small  Bore,  Long  Stroke  Cylinder 128 

Fig.  62. — End  View  Humber  (English)  Motor  Depicting  Off-set  Cylinder 

Construction '  129 

Fig.  63. — Diagrams  Demonstrating  Advantages  of  Off-set  Crank  Shaft 

Construction  131 


List  of  Illustrations  13 

PAGE 

Fig.  64. — Part  Sectional  View  of  Sheffield  Simplex  Six-Cylinder  Motor 
Showing  Use  of  Block  Castings,  Seven-Bearing  Crank  Shaft  and 
Other  Constructional  Details.  Note  Exceptionally  Good  Water- 
jacketing  of  Cylinders  .  . 132 

Fig.  65. — Section  Through  Typical  Four-Cylinder  Block  Motor  with 

Three-Bearing  Crank  Shaft 133 

Fig.  66. — Sectional  View  Knox  Model  R  Motor  Illustrating  Application 
of  Individual  Cylinder  Castings,  Separable  Head  Members  and  Five- 
Bearing  Crank  Shaft.  A  Simple  and  Substantial  Design  that  is  En- 
during and  Efficient 134 

Fig.  67. — Sectional  View  of  Typical  Four-Cylinder  Motor  Using  Indi- 
vidual Cylinder  Castings  with  Cylinder  Heads  Cast  Integral.  Gen- 
eral Design  Fair,  Excepting  that  of  Connecting  Rods  ...  135 

Fig.  68. — Illustrating  Typical  Methods  of  Valve  Installation  in  Internal 
Combustion  Motors.  A — Valves  on  Opposite  Sides  of  T  Head 
Cylinder.  B — L  Head  Cylinder  Having  Intake  Valve  Placed  Di- 
rectly in  the  Center  of  the  Cylinder  Head 138 

Fig.  69. — Benz  Racing  Motor,  Presented  to  Show  Method  of  Valve 

Placing  so  These  Members  Open  Directly  into  the  Cylinder  Head  .  139 

Fig.  70. — Part  Sectional  View  of  Bergdoll  Motor  Showing  Placing  of 
Valves.  The  Exhaust  Member  is  Fitted  in  a  Side  Pocket  of  the  L 
Cylinder.  The  Inlet  Valve  is  Placed  Directly  in  the  Center  of  the 
Combustion  Chamber  ..........  141 

Fig.  71. — Cylinder  Head  of  Knox  Engine  Cut  in  Two  to  Show  Method  of 
Valve  Placing  and  Seating  Directly  in  Separately  Cast  Member. 
Valves  Operated  by  Rocker  Arms.  Note  Exceptionally  Good  Water 
Spaces  Around  Valve  Seats 142 

Fig.  72. — Section  Through  Concentric  Valve  Used  on  Some  Franklin 
Models.  The  Exhaust  Valve,  which  is  a  Regular  Poppet  Type, 
Seats  in  the  Inlet  Member,  which  is  a  Hollow  Shell  of  Metal.  Both 
Valves  Open  Directly  into  the  Combustion  Chamber  .  .  .  143 

Fig.  73. — Section  Through  Cylinder  of  Hudson  Car.  A  Typical  Form 
Having  L  Shape  Cylinder  with  Inlet  and  Exhaust  Valves  on  Same 
Side  of  Cylinder  and  Actuated  from  Common  Cam  Shaft.  Note 
Plate  Used  to  Enclose  Valve  Springs 144 

Fig.  74. — Types  of  Valves  in  Common  Use.  A— One-Piece  Steel  Valve  of 
Good  Design  which  Permits  Easy  Gas  Flow.  B — Steel  Valve  Made 
by  Electrically  Welding  a  Nickel  Steel  Head  to  a  Carbon  Steel  Stem. 
C — A  Construction  Often  Employed  for  Exhaust  Valves,  a  Two- 
Piece  Built-Up  Member.  D — Valve  with  Flat  Seat,  Often  Used  to 
Admit  Mixture  to  Cylinder  .  . 146 

Fig.  75. — Forms  of  Valve-Lifting  Cams  Generally  Employed.  A — Cam 
Profile  for  Long  Dwell  and  Quick  Lift.  B — Typical  Inlet  Cam  Used 


14  List  of  Illustrations 

PAGE 

with  Mushroom  Type  Follower.  C — Average  Form  of  Cam.  D — 
Designed  to  Give  Quick  Lift  and  Gradual  Closing  .  .  .  148 

Fig.  76. — Showing  Principal  Types  of  Cam  Followers  which  Have  Re- 
ceived General  Application  149 

Fig.  77. — Defining  Different  Possible  Methods  of  Valve  Operation.  A — 
Overhead  Valve  Actuated  by  Rocker  Arm,  Tappet  Rod  and  Roller 
Type  Cam  Follower.  B — Both  Valves  Operated  from  One  Cam,  T 
Head  Cylinder.  C — Valves  of  L  Type  Twin  Cylinder  Casting 
Operated  by  Mushroom  Type  Cam  Followers.  D — Suggested 
Method  of  Indirect  Valve  Operation 151 

Fig.  78. — Diagram  Showing  Forms  of  Cylinder  Demanded  by  Different 
Valve  Placings.  A — T  Head  Type,  Valves  on  Opposite  Sides.  B — L 
Head  Cylinder,  Valves  Side  by  Side.  C — L  Head  Cylinder,  One 
Valve  in  Head,  Other  in  Pocket.  D — Inlet  Valve  Over  Exhaust 
Member,  Both  in  Side  Pocket.  E — Valve-in-the-Head  Type  with 
Vertical  Valves.  F — Inclined  Valves  Placed  to  Open  Directly  into 
Combustion  Chamber 153 

Fig.  79. — Cam  Shaft  and  Valve  Operating  Plunger  Case  of  Hupp  Motor, 

a  Separate  Member.  Note  Simple  Type  of  Cam  Follower  .  .  154 

Fig.  80. — Front  View  of  Warren-Detroit  "  30  "  Motor  with  Timing  Gear 
Case  Cover  Removed  to  Show  Arrangement  of  Cam  Shaft  and  Water 
Pump  Driving  Gears 156 

Fig.  81. — Showing  Use  of  Silent  Chain  Connection  Between  Crank  Shaft 
and  Cam  Shaft,  and  also,  for  Driving  Water  Pump  and  Magneto 
Shafts.  A— Chain  Drive  on  Wolseley  (English)  1912  Motor.  B — 
Method  of  Using  Silent  Chains  on  White  &  Poppe  (English)  Power 
Plant  .  .  ' 157 

Fig.  82. — Section  Through  Cylinder  of  Knight  Motor  Showing  Important 

Parts  of  Valve  Motion  .  159 

Fig.  83. — Diagram  Showing  Relative  Movement  of  Sleeves  and  Cam  Shaft 
of  Knight  Type  Motor.  Note  Port  Opening  at  Various  Piston  Posi- 
tions. ^Shaded  Portions  of  Sleeves  Represent  Ports  .  .  .  160 

Fig.  84. — Sectional  Views  Showing  Action  of  Miesse  Combination  Sleeve 

and  Piston  Valve  at  Different  Points  in  Cycle  of  Engine  Operation  162 

Fig.  85. — Denning  Action  of  Peculiar  Rotary  Valve  Used  in  Latest  Itala 

(Italian)  Motor  .  164 

Fig.  86. — Partial  Section  of  Reynolds  Rotary  Valve  Motor  Cylinder 
Showing  Method  of  Rotating  Simple  Disk  Valve  and  Ports  in 
Cylinder  Head 165 

Fig.  87. — Part  Section  of  Reynolds  Rotary  Valve  Motor  Showing  Prac- 
tical Application  of  Ported  Disk  in  Controlling  Gas  Passages.  Note 
Compact  Design  of  Cylinder  Block  and  Two-Bearing  Four-Throw 
Crank  Shaft  .  167 


List  of  Illustrations  15 

PAGE 

Fig.  88. — Unconventional  Forms  of  Rotary  Valve  Motors  Designed  to 
Meet  the  Present  Day  Demand  for  Silent  Valve  Action.  A — Mead 
Motor  Using  Two  Revolving  Cylindrical  Valves,  One  at  Each  Side  of 
Cylinder.  B— Single  Ported  Cone  Valve.  C — Application  of  Two 
Single  Ported  Cones,  One  Superposed.  D — Use  of  Distinct  Valves, 
One  for  Inlet  Port,  the  Other  to  Govern  Exhaust  Passage  .  .  168 

Fig.  89. — Part  Section  of  Sphinx  Valvelcss  Motor  in  which  Poppet  Valves 
are  Replaced  by  a  Split  Ring  which  Reciprocates  in  the  Cylinder 
Head,  Opening  and  Closing  the  Gas  Ports  as  it  Moves  Up  and 
Down.  A — Inlet  Ports  Open.  B  and  C — All  Ports  Closed.  D — 
Exhaust  Ports  Open 170 

Fig.  90. — Diagrams  Illustrating  Action  of  Darracq  (French)  D  Form 
Rotary  Valve  Motor.  A — Piston  at  Beginning  of  Induction  Stroke. 
B — Piston  at  Inception  of  Compression  Stroke.  C — Piston  in  Posi- 
tion for  Receiving  Explosion  Impact.  D — Valve  Position  at  Start 
of  Exhaust  Period 172 

Fig.  91. — Section  of  Hewitt  Piston  Valve,  Motor  Cylinder  and  Valve 

Chest  '  .  174 

Fig.  92. — Hewitt  Piston  Valve  Motor  Action  Outlined  Graphically.  A — 

Suction  Stroke.  B— Compression.  C — Explosion.  D — Exhaust  .  175 

Fig.  93. — Diagram  Showing  Different  Valve  Timing  Methods          .         .          182 

Fig.  94. — Diagram  Showing  Method  of  Marking  Fly-wheel  Circumference 

to  Obtain  Proper  Timing  of  Typical  Four-Cylinder  Motor  .  .  184 

CHAPTER    IV 

Fig.  95. — Forms  of  Pistons  Commonly  Employed  in  Gasoline  Engines. 
A — Dome  Head  Piston  with  Three  Packing  Rings.  B — Flat  Top 
Form  Almost  Universally  Used.  C — Concave  Piston  Utilized  in 
Knight  Motors  and  Some  Having  Overhead  Valves.  D — Two-Cycle 
Engine  Member  with  Deflector  Plate  Cast  Integrally.  E — Differ- 
ential or  Two-Diameter  Piston  Used  in  Some  Engines  Operating  on 
Two-Cycle  Principle  .  187 

Fig.  96. — Typical  Methods  of  Piston  Pin  Retention  Generally  Used  in 
Engines  of  American  Design.  A — Single  Set  Screw  and  Lock  Nut. 
B — Set  Screw  and  Check  Nut  Fitting  Groove  in  Wristpin.  C,  D — 
Two  Locking  Screws  Passing  into  Interior  of  Hollow  Wristpin.  E — 
Split  Ring  Holds  Pin  in  Place.  F— Use  of  Taper  Expanding  Plugs 
Outlined.  G — Spring  Pressed  Plunger  Type.  H — Piston  Pin  Pinned 
to  Connecting  Rod.  I — Wristpin  Clamped  in  Connecting  Rod,  Small 
End  by  Bolt 189 

Fig.  97. — Types  of  Piston  Rings  and  Ring  Joints.  A — Eccentric  Ring. 
B — Concentrically  Machined  Form.  C — Lap  Joint  Ring.  D — Butt 
Joint,  Seldom  Used.  E — Diagonal  Cut  Member,  a  Popular  Form  191 


16  List  of  Illustrations 

PAGE 

Fig.  98. — Showing  Flat  Top  Piston  Provided  with  Four  Concentric  Rings, 

One  of  the  Packing  Members  and  the  Wristpin  with  its  Bushing  .  192 

Fjgt  99. — Typical  Connecting  Rod  and  its  Wristpin.  Lower  Bearing  Cap 

Held  by  Four  Bolts.  White  Metal  Boxes  in  Cast  Bronze  Rod  .  193 

Fig.  100. — Connecting  Rod  Types  Summarized.  A — Simple  Connecting 
Rod  Made  in  One  Piece,  Usually  Fitted  in  Small  Single-Cylinder 
Engines  Having  Built-up  Crank  Shafts.  B — Marine  Type,  a  Pop- 
ular Form  on  Heavy  Engines.  C — Conventional  Automobile  Type,  a 
Modified  Marine  Form.  D — Type  Having  Hinged  Lower  Cap  and 
Split  Wristpin  Bushing.  E — Connecting  Rod  Having  Diagonally 
Divided  Big  End.  F — Ball  Bearing  Rod.  G — Sections  Showing 
Structural  Shapes  Commonly  Employed  in  Connecting  Rod  Con- 
struction   195 

Fig.  101. — Crank  Shaft,  Piston  and  Connecting  Rod  Assembly  Used  in 

Reo  Motors 196 

Fig.  102. — Some  of  the  Components  of  Corbin  "  40  "  Motor.  A — Piston 
and  Connecting  Rod  Assembly.  B — Inlet  and  Exhaust  Cam  Shafts. 
C — Twin  Cylinder  Casting 197 

Fig.  103. — Typical  Cam  Shaft  with  Valve  Lifting  Cams  and  Gears  to  Op- 
erate Auxiliary  Devices  Forged  Integrally 198 

Fig.  104. — Auxiliary  Shaft  Used  in  Connection  with  Cam  Shaft  Driven 

from  a  Spiral  Gear  Turns  Timer  and  Oil  Pump  ....  199 

Fig.  105. — Showing  Method  of  Making  Crank  Shaft.  A — The  Rough 
Steel  Forging  Before  Machining.  B — The  Finished  Six-Throw, 
Seven-Bearing  Crank  Shaft .  200 

Fig.  106. — Denning  Built-Up  Crankshaft  Construction  Sometimes  Used  in 

Small  Motors 201 

Fig.  107. — Showing  Form  of  Crank  Shaft  for  Twin-Cylinder  Opposed 

Power  Plant  .  .  .  .  . 202 

Fig.  108. — Two  Forms  of  Four-Cylinder  Crank  Shaft.  A — Five-Bearing 
Type  with  Fly-wheel  Fastening  Key  at  Front  End.  B — Three-Bear- 
ing Type  with  Flange  for  Securing  Fly- Wheel  Formed  Integral  .  202 

Fig.  109. — Representative  Three-Bearing  Crank  Shafts.  A — For  Use  with 
Cylinders  Cast  in  Pairs.  B — Used  with  Individually  Cast  Cylin- 
ders. Note  Round  Section  Portions  Connecting  Ends  to  Center 
Crank  Throws  .  . 203 

Fig.  110. — Bottom  View  of  Premier  Engine  Showing  Four-Bearing  Six- 
Cylinder  Crank  Shaft  with  Connecting  Rods  in  Place  .  .  .  204 

Fig.  111. — Design  of  Four-Cylinder  Crank  Shaft  Mounted  on  Two  An- 
nular Ball  Bearings.  Note  Method  of  Fly- Wheel  Retention  by  Key 
and  Taper  and  Bearing  Housing ,  204 

Fig.  112.— Four-Throw,  Two-Bearing  Chalmers  Crank  Shaft  Mounted  on 

Anti-Friction  Journals  of  the  Ball-Bearing  Type  .  .  .  .  205 


List  of  Illustrations  17 

PAGE 

Fig.  113. — Four-Throw,  Three-Bearing  Lozier  Crank  Shaft  and  Connecting 
Rod  Assembly  Mounted  on  Three  Large  Annular  Ball  Bearings. 
Note  Connecting  Rod  Design  and  the  Use  of  Plain  Bearings  at  Both 
Wristpin  and  Crankpin  Ends 206 

Fig.  114. — Typical  Fly-wheel  Showing  Female  Member  of  Cone  Clutch 

and  Fan  Blade  Spokes.  Rim  is  Light  Because  of  Large  Diameter  208 

Fig.  115. — Rear  View  of  Overland  Power  Plant  Showing  Fan  Blade  Spoke 

Fly-wheel  Construction  209 

Fig.  116. — Outlining  Methods  of  Fly-wheel  Retention  Commonly  Used. 
A — By  Gib  Key.  B — By  Woodruff  Key,  Taper  and  Clamp  Nut. 
C — By  Bolting  to  Flange  Forged  Integrally  with  Crank  Shaft  .  211 

Fig.  117. — Showing  Method  of  Marking  Rim  of  Six-Cylinder  Fly-wheel 
for  Guiding  Repairman  or  Motorist  to  Retain  Correct  Valve 
Timing 212 

Fig.  118. — Crank  Case  of  Reo  Four-Cylinder  Motor,  a  Barrel  Type  with 

Ends  Closed  by  Plates  which  Support  Crank  Shaft  .  .  .  214 

Fig.  119. — Crank  Case  of  Corbin  "  40  "  Power  Plant  Made  in  Two  Halves. 
Crankshaft  Bearings  and  Caps  Secured  to  Upper  Half,  which  also 
Has  Supporting  Arms  Cast  Integral.  Lower  Portion  of  Crank  Case 
Simply  Acts  as  Oil  Container.  This  is  the  Common  Construction  215 

Fig.  120. — Bottom  View  of  Inter-State  Power  Plant.  Crank  Case  a  Barrel 
Form  with  Removable  Bottom  Plate  to  Permit  Access  to  Engine 
Interior.  Important  Power  Plant  Parts  Gnarly  Shown  .  .  .  216 

Fig.  121. — Top  Half  of  Knox  Crank  Case.  Note  Method  of  Supporting 
Five-Bearing  Crank  Shaft  and  Substantial  Yoke  Encircling  Space 
for  Fly-wheel  and  Serving  to  Hold  Transmission  Gearing  to  Form 
Unit  Power  Plant 217 

Fig.  122. — Sectional  Views  of  Amplex  Two-Cycle  Motor  Cylinder.  A — 
Piston  at  Top  of  Stroke,  Ready  to  Receive  Impact  Due  to  Gas  Ex- 
plosion. B — Piston  at  Bottom  of  Stroke.  Note  Gas  Transfer 
from  Engine  Base  and  Expulsion  of  Burnt  Gases  .  .  .  .  219 

Fig.  123. — Sectional  View  Showing  Construction  of  Legros  (French) 

Motor  Defining  Peculiar  Cylinder  Construction  .  .  .  .  221 

Fig.  124. — The  Cote  (French)  Two-Cycle  Motor  is  a  Good  Example  of 
the  Type  Employing  a  Two-Diameter  Piston  and  Distributor 
Valve 222 

Fig.  125. — The  Rayner  (English)  Two-Cycle  Motor  Employs  Distinctive 
Double-Piston  Arrangement.  A — Side  View  Showing  Crank  Shaft 
and  Connecting  Rods.  B — End  Section  Showing  Relative  Angu- 
larity of  Connecting  Rods.  C — Inner  Piston  Uncovers  Inlet  Ports, 
Outer  Piston  Covers  Exhaust  Passages 223 

Fig.  126. — Inlet  Side  of  Typical  Four-Cylinder  Power  Plant  Showing 

Carburetor  and  Magneto  Placing 225 


18  List  of  Illustrations 

PAGE 

Fig.  127. — Exhaust  Side  of  Four-Cylinder  Power  Plant  Showing  Water 

Pump  Location 226 

Fig.  128. — Valve  Side  Regal  Motor  Showing  Compactness  of  Design  Pos- 
sible with  L  Cylinder  Construction.  Note  Manifold  Placing  and 
Magneto  and  Carburetor  Location 226 

Fig.  129. — Exhaust  Side  of  Columbia  ''Mark  85"  Motor.  Note  En- 
closed Valve  Springs  and  Arrangement  of  Parts  ....  227 

Fig.  130. — Inlet  Side  of  Matheson  "  Silent  Six  "  Power  Plant,  an  Over- 
head Valve  Type 228 

Fig.  131. — View  of  Eight-Cylinder  Hendee  Motor,  a  Type  Seldom  Used 
on  Motor  Cars,  but  Popular  for  Aviation.  Eight-Cylinder  Mo- 
tors Designed  for  Automobile  Propulsion  are  Always  of  the  V  Type, 
which  Permits  Compactness  and  no  Greater  Overall  than  the  Usual 
Four-Cylinder  Power  Unit 229 


CHAPTER    V 

Fig.  132. — Illustrating  Method  of  Storing  Fuel  in  Brush  Runabout,  which 

Permits  Short  and  Direct  Gasoline  Piping 242 

Fig.  133. — Denning  the  Usual  Met'hods  of  Fuel  Storage  in  Motor  Cars. 
A — Oval  Tank  Back  of  Seat.  B — Round  Tank  at  Rear  of  Chassis, 
Common  on  Racing  Cars.  C — Container  Under  Front  Seat,  the 
Conventional  Method.  D — Tank  at  Rear  of  Frame,  Underslung, 
which  Makes  Pressure  Feed  Necessary 243 

Fig.  134. — Complete  Fuel  System  Used  on  Some  Models  of  Peerless  Cars, 
Showing  Method  of  Supplying  Carburetor  with  Fuel  and  Joining  It 
to  Cylinders 245 

Fig.  135. — Unconventional  System  in  which  a  Pump  is  Depended  Upon 

to  Draw  Fuel  from  Container  and  Deliver  It  to  Vaporizer  .  .  246 

Fig.  136. — First  Forms  of  Gasoline  Vaporizers.  A — An  Early  Wick  Car- 
buretor. B — Type  in  which  Air  is  Drawn  Through  Fuel  to  Charge 
It  with  Explosive  Vapor  . 248 

Fig.  137. — Marine  Type  Mixing  Valve,  by  which  Gasoline  is  Sprayed  into 

Air  Stream  Through  Small  Opening  in  Air  Valve  Seat  .  .  .  250 

Fig.  138.— Lanchester  Wick  Feed  Carburetor.  The  Only  Modern  Adapta- 
tion of  Earlier  Forms 251 

Fig.  139. — Tracing  Evolution  of  Modern  Spray  Carburetor.  A — Early 
Form  Evolved  by  Maybach.  B — Phoenix-Daimler  Modification  of 
Maybach's  Principle.  C — Modern  Concentric  Float  Automatic  Com- 
pensating Carburetor 253 

Fig.  140. — Showing  Common  Forms  of  Mixing  Chambers  and  Spray  Noz- 
zle Locations 257 

Fig.  141. — Types  of  Float  Chambers  in  Common  Use  Defining  Various 

Methods  of  Controlling  Fuel  Supply  Valve 259 


List  of  Illustrations  19 

PAGE 

Fig.  142. — Spray  Nozzle  Forms  and  Methods  of  Supplying  Auxiliary  Air 

to  Modern  Carburetors 261 

Fig.  143. — Showing  Method  of  Regulating  Fuel  Mixture  Supplied  the  Cyl- 
inders by  Means  of  Centrifugal  Governor,  which  Automatically  Re- 
duces the  Quantity  when  Engine  Speed  Exceeds  a  Certain  Predeter- 
mined Limit 263 

Fig.  144. — Schebler  Carburetor  Construction  Outlined.  This  is  One  of  the 

Simplest  Forms  that  Have  Been  Used  Extensively  ....  265 

Fig.  145. — Kingston  Automatic  Carburetor  Admits  Auxiliary  Air 

Through  Ball-Controlled  Ports  at  Side  of  Mixing  Chamber  .  .  266 

Fig.  146. — Holley  Carburetor  with  Spring  Controlled  Poppet  Valve  to 

Regulate  Auxiliary  Air  Passage 267 

Fig.  147. — Latest  Model  of  Holley  Carburetor  with  By-Pass  Tube  to  Pro- 
vide Easier  Starting 269 

Fig.  148. — Mercedes  Carburetor,  which  Has  Retained  Substantially  the 

Same  Form  as  when  First  Designed  Nearly  a  Decade  Ago  .  .  270 

Fig.  149. — Sectional  View  of  Chapin  Carburetor,  which  Has  Mechanical 

Control  of  Auxiliary  Air  Opening  and  Spray  Nozzle  Needle  .  .  271 

Fig.  150. — Sectional  View  of  Excelsior  Carburetor.  A — Side  Section  De- 
picting Floating  Ball  Controlling  Mixture  Passage.  B — Showing 
Peculiar  Air  Valve  Spring  and  Geared  Control  of  Air  Valve  Stem  272 

Fig.  151. — Views  of  the  Efficient  Vaporizer  Used  on  Fierce-Arrow  Cars, 
Showing  Method  of  Fuel  Regulation,  Auxiliary  Air  Control  by 
Reeds,  and  Mixture  Supply  Regulation  by  Cylindrical  Throttle 
Valve  .  • 274 

Fig.  152. — Grouvelle  and  Arquemburg  (French)  Carburetor  with  Venturi 

Tube  Mixing  Chamber  and  Air  Port  Control  by  Floating  Balls  .  275 

Fig.  153. — Peerless  Carburetor,  which  is  Combined  with  Induction  Mani- 
fold. Has  Spray  Nozzle  and  Float  Chamber  at  Bottom  and  Air 
Valve  at  Top 277 

Fig.  154. — Showing  Details  of  Breeze  Carburetor,  a  Simple,  Automatic 
Instrument.  Note  Fuel  Adjustment  by  Needle  Valve  Over  Spray 
Nozzle 279 

Fig.  155. — Details  of  Stromberg  Double-Jet  Carburetor,  which  Provides 

Extra  Fuel  Through  Auxiliary  Spray  Jet  when  Motor  Demands  It  280 

Fig.  156. — Carburetor  Incorporated  in  F.  I.  A.  T.  Cylinder  Casting  is  a 

Multiple-Jet  Type  Having  Two  Spray  Tubes 281 

Fig.  157. — Denning  Principles  of  Construction  Incorporated  in  Saurer 
Economy  Carburetor,  a  Two-Jet  Form  Having  Automatic  Control  of 
Mixture 283 

Fig.  158. — The  Zenith  Carburetor,  which  Embodies  Novel  Application  of 
Double-Jet  Principle,  One  Spray  Nozzle  Being  Concentric  with  the 
Other  285 


20  List  of  Illustrations 


PAGE 


Fig.  159. — Types  of  Strainers  Interposed  Between  Vaporizer  and  Gasoline 

Tank  to  Prevent  Water  or  Dirt  Passing  Into  Carbureting  Device  .  287 

Fig.  160. — Holley  Combined  Gasoline  and  Kerosene  Carburetor  May  Be 
Used  with  Either  Fuel  Though  Specially  Adapted  for  the  Less  Vola- 
tile Liquid  Distillates  of  Petroleum,  Because  of  Preheating  Ar- 
rangement   289 

Fig.  161. — Combined  Intake  and  Exhaust  Manifold  Suggested  as  Suit- 
able for  Use  with  Kerosene  and  Air  Mixture.  The  Hot  Exhaust 
Gases  Heat  the  Inlet  Pipe  Walls  and  Produce  More  Complete  Va- 
porization  290 

Fig.  162. — Showing  Two-Cycle  Motor  with  Device  for  Direct  Injection  of 

Heavier  Petroleum  Distillates  into  Cylinder 292 

Fig.  163. — Typical  Induction  Pipes  Used  on  Four-Cylinder  Motors       .         295 

Fig.  164. — Conventional  Inlet  Manifolds  Adapted  for  Six-Cylinder  Motors     296 

Fig.  165. — Some  Unconventional  Forms  of  Gas  Supply  Pipes  Used  on 

Six-Cylinder  Power  Plants 297 

Fig.  166. — Holley  Method  of  Compensating  for  Temperature  Variations 
and  Securing  Easy  Starting  from  Dash-Adjusted  Regulator.  Posi- 
tions of  Regulator  Valve  Sleeve  for  Different  Conditions  Outlined  299 

Fig.  167. — Muffler  Forms  Adapted  to  Reduce  Pressure  of  Exhaust  Gases 

Before  Discharging  Them 301 

Fig.  168. — Water-Cooled  Muffler  Used  when  Exceptional  Silence  is  De- 
sired. Often  Applied  in  Marine  Service 303 

Fig.  169. — Suggested  Exhaust  Manifold  in  which  Ejector  Action  of  Ex- 
haust Gases  Under  High  Velocity  is  Said  to  Reduce  Back  Pressure 
on  Pistons 304 

Fig.  170. — How  Muffler  Cut-out  Valve  is  Arranged  on  Wolseley  (English) 

Cars  to  Reduce  Noisy  Direct  Exhaust 305 

CHAPTER    VI 

Fig.  171.— Simple  Primary  Cells  Used  to  Produce  Electric  Current.  A — 
Form  to  Show  Principle  of  Current  Production  by  Chemical  Ac- 
tion. B — Dry  Cell,  the  Type  Suitable  for  Automobile  Service  .  309 

Fig.  172. — Methods  of  Joining  Dry  Cells  to  Form  Batteries  of  Varying 

Value  .  .  * 311 

Fig.  173. — Types  of  Accumulators  or  Storage  Batteries.  A — Simple  Form 
of  Cell.  B — Battery  Composed  of  Three  Cells,  Such  as  Commonly 
Used  for  Motor  Car  Engine  Ignition 314 

Fig.  174. — Gray  &  Davis  Governed  Dynamo,  an  Appliance  for  Producing 

Electricity  by  Mechanical  Means 31!) 

Fig.  175. — Distinctive  Form  of  Current  Producer  Used  on  Ford  Cars  is 

Incorporated  in  the  Power  Plant  Fly-Wheel 320 

Fig.  176. — Simple  Forms  of  Contact  Breakers  Used  on  One-Cylinder  En- 
gines. A — Wipe  Contact.  B — Touch  Contact 323 


List  of  Illustrations  21 

PAGE 

Fig.  177. — Timers  Employed  on  Four-Cylinder  Engines.  A — Four-Contact 
Device  for  Commutating  Primary  Current.  B — Combined  Timer 
and  Distributor  Directs  Both  High  and  Low  Tension  P^nergy .  .  324 

Fig.  178. — Showing  Disposition  of  Contact  Points  on  Timers  for  Differ- 
ing Numbers  of  Cylinders.  A — One-Cylinder  Type.  B — Arrange- 
ment for  Two-Cylinder  Opposed  Motor.  C — Contacts  Separated  by 
90  Degrees  in  One  Direction  and  270  Degrees  in  the  Other  when 
Used  on  Two-Cylinder  Vertical  Engine  with  Opposed  Crank-Pins. 
D — Three-Cylinder  Form.  E — Suitable  for  Four-Cylinder  Engines. 
F — Type  Employed  on  Six-Cylinder  Power  Plants  ....  325 

Fig.  179. — Simple  Ignition  System  for  One-Cylinder  Motor  Showing 

Important  Components  and  Their  Relation  to  Each  Other  .  .  327 

Fig.  180. — Part  Sectional  View  of  Simple  Induction  Coil,  an  Important 
Component  of  All  Battery  Ignition  Groups  and  Sometimes  Used 
with  Magnetos 329 

Fig.  181. — Conventional  Induction  Coil  Forms.  A — Coil  Unit  and  Plug 
Combined.  B — Simple  Box  Coil  for  One-Cylinder  Ignition.  C — 
Two-Unit  Coil  for  Two-Cylinder  Motors.  D— Four-Unit  Coil  for 
Four-Cylinder  Service 331 

Fig.  182. — Spark  Plug  Construction  Outlined.  A — Sectional  View  of 

Porcelain  Plug.  B — Part  Sectional  View  of  Mica  Plug  .  .  333 

Fig.  183. — Three  Forms  of  Spark  Plugs  in  .which  Electrodes  are  Sep- 
arated by  Porcelain  Insulation 334 

Fig.  184. — Methods  of  Installing  Spark  Plugs  of  Conventional  Form. 
A — Incorrect  Method.  B — Correct  Installation  in  Valve  Chamber 
Cap.  C — Combined  with  Cylinder  Priming  Device  or  Compression 
Relief  Cock 335 

Fig.  185. — Novel  Spark  Plugs  and  Accessory  Parts.  A — Spark  Gap 
Designed  to  be  Placed  in  Series  with  Plug  Electrode  and  Current 
Source.  B — Plug  Shell  with  Glass  Insets  to  Show  Spark.  C — 
Spark  Plug  with  Waterproof  Terminal  Cover  ....  337 

Fig.  186.— Double  Pole  Spark  Plug  and  Method  of  Applying  It  to  Obtain 

Two  Sparks  in  the  Cylinder 340 

Fig.  187. — Assembly  View  of  Four-Cylinder  Ignition  Group  Showing  All 

Devices  and  Methods  of  Wiring 341 

Fig.  188. — Method  of  Employing  Single  Coil  to  Fire  Four  Cylinders 

when  Secondary  Current  is  Distributed  Instead  of  Battery  Energy  342 

Fig.  189. — Distributor  and  Coil  Ignition  Group  for  Six-Cylinder  Motor 

Showing  Order  of  Firing  and  Wiring  Connections  Clearly  .  .  343 

Fig.  190. — Low-Tension  Igniter  Plate  by  which  Spark  is  Produced  in 
Some  Locomobile  Engine  Cylinders.  A — External  View  Showing 
Rocker  Arm.  B — Interior  View  Depicting  Contact  Points.  C — 
Method  of  Operation  .  344 


22  List  of  Illustrations 


PAGE 


Fig.  191. — Low-Tension  Ignition  System  for  Four-Cylinder  Motor  Utilizes 
Battery  and  Magneto  for  Current  Production.  Note  Simple  Wir- 
ing. All  Conductors  Conveying  Low-Tension  Current  .  .  .  346 

Fig.  192. — Simple  High-Tension  Magneto  for  One-Cylinder  Ignition.  A 
Complete  Apparatus  Comprising  Source  of  Current  and  Timing  De- 
vice as  Well 347 

Fig.  193. — How  Distributor  Contacts  are  Spaced  on  Two-,  Three-,  Four- 

and  Six-Cylinder  Magnetos 349 

Fig.  194. — Partially  Dismantled  Four-Cylinder  Magneto  Showing  Impor- 
tant Parts  of  Current  Producing  and  Distributing  Elements  .  .  351 

Fig.  195. — Simple  Wiring  Scheme  when  Four-Cylinder  Magneto  is 
Utilized  for  Gas  Engine  Ignition.  Magneto  Members  Shown  Sep- 
arate to  Facilitate  Explanation  of  Principles  of  Operation  .  .  352 

Fig.  196. — Side  Sectional  View  of  Bosch  High-Tension  Magneto  Shows 
Disposition  of  Parts.  End  Elevation  Depicts  Arrangement  of  Inter- 
rupter and  Distributor  Mechanism 353 

Fig.  197. — Wiring  Diagram  Outlining  Method  of  Combining  Magneto  and 

Transformer  Coil  to  Form  Device  for  Four-Cylinder  Ignition  .  354 

Fig.  198. — Defining  Construction  of  Connecticut  Magneto,  a  Form  in 
which  Transformer  Coil  is  Placed  Between  Magnets  Above  Arma- 
ture Tunnel 355 

Fig.  199. — Showing  Application  of  High-Tension  Principle  in  K.W.  Four- 
Cylinder  Magneto  .  356 

Fig.  200. — K.W.  High-Tension  Magneto,  a  Distinctive  Form  Utilizing 
Stationary  Winding  and  Revolving  Inductor  Elements  to  Produce 
Current  for  Ignition  . 357 

Fig.  201. — Typical  American  Magneto  Forms.  A — Heinze  Machine  with 
Round  Section  Field  Magnets.  B — Kingston  Magneto  for  Dual  Igni- 
tion. C — Clean-Cut  Design  of  Connecticut  Device.  D— Splitdorf 
Double  Distributor  Form  Designed  for  Two-Spark  Ignition  Systems  3*59 

Fig.  202. — Conventional  Methods  of  Placing  and  Driving  Magneto  Genera- 
tors. A— System  Used  on  Regal  Engine.  B — Magneto  is  Driven 
from  Pump  Shaft  Extension  on  Velie  Motors 300 

Fig.  203. — Simple  Methods  of  Holding  Magneto  in  Place  on  Engine  Base 

to  Permit  of  Easy  Removal  of  Apparatus  when  Desired  .  .  302 

Fig.  204. — The  Ford  Magneto  is  Integral  with  Engine  Base,  and  Revolv- 
ing Magnets  are  Attached  to  Fly-wheel.  Thus  Direct  Drive  from 
Crank  Shaft  is  Possible  Without  Gears  .  .  .  .  .  .  .  303 

Fig.  205. — Double  Ignition  System  Utilizing  Battery  and  Induction  Coil 
Group  for  Starting  and  Emergency  Service,  and  Pittsfield  High  Ten- 
sion Magneto  as  the  Main  Ignition  System 364 

Fig.  206. — Practical  Application  of  Double  Ignition  System  to  Four- 
Cylinder  Power  Plant 365 


List  of  Illustrations  23 

PAGE 

Fig.  207. — Method  of  Applying  Bosch  Dual  Ignition  System  to  Conven- 
tional Four-Cylinder  Power  Plant 366 

CHAPTER   VII 

Fig.  208. — Showing  Use  of  Magnifying  Glass  to  Demonstrate  that  Ap- 
parently Smooth  Metal  Surfaces  May  Have  Minute  Irregularities 
which  Produce  Friction ^.  369 

Fig.  209.— Simple  Gravity-Feed  Oil  Cups  with  Glass  Body  to  Show  Height 
of  Lubricant  in  Container,  and  Sight  Gauges  to  Give  Visible  Evidence 
of  Amount  of  Oil  Supplied 375 

Fig.  210. — Positive  Mechanical  Methods  of  Supplying  Lubricant.  A — 
Worm  Gear  Driven  Plunger  Pump  Oiler.  B — Gear  Pump  with  High- 
Pressure  Relief  Valve  .  377 

Fig.  211. — How  Oil  may  be  Supplied  to  Interior  Mechanism  of  Internal 
Combustion  Motor.  A — Oil  Pick-up  Finger  on  Connecting  Rod  End 
Dips  into  Lubricant  and  Splashes  it  Over  Interior  Parts.  B — Oil 
Drops  into  Channel  in  Horizontal  Connecting  Rod  and  Supplies  Bear- 
igs  and  Cylinder 378 

Fig.  212. — Sectional  View  of  Typical  Motor  Showing  Parts  Needing 
Lubrication  and  Method  of  Applying  Oil  by  Constant  Level  Splash 
System.  Note  also  Water-jacket  and  Spaces  for  AVater  Circula- 
tion  380 

Fig.  213. — Sectional  View  of  Part  of  Rutenber  Engine  Depicting  Method 

of  Driving  Oil  Pump  and  Distribution  to  Bearing  Points  .  .  381 

Fig.  214. — Oil  Distributing  System  Employed  on  Stoddard-Dayton  Motor 

Cars 382 

Fig.  215. — Part  Sectional  View  of  Motor  Car  Engine  Showing  Oil  Dis- 
tribution by  Splashers  at  the  Ends  of  the  Connecting  Rods,  which 
Dip  into  Troughs  Disposed  Under  Them 383 

Fig.  216. — Method  of  Supplying  Oil  Under  Pressure  to  Main  Bearings, 
from  which  it  is  Directed  to  Connecting  Rods  by  Passages  Drilled 
in  Crank  Shaft 384 

Fig.  217. — Showing  Application  of  Mechanical  Oiler  having  individual 
Pumps  and  Leads  to  Bearing  Points  in  Connection  with  Sight-Feed 
Gauge  on  Dash 385 

Fig.  218. — Oil  Supply  System  Utilized  on  Knox  Automobile  Power  Plants 

has  Many  Good  Features 386 

Fig.  219.— Constant  Level  Positive  Supply  System  Used  in  Columbia 

"Mark  85"  Motor 387 

Fig.  220. — Components  of  Typical  Motor  Car  Cooling  Group  Utilizing 
Pump  to  Maintain  Circulation  of  Liquid.  System  Shown  Used  on 
Peerless  Cars  with  Success 390 


24  List  of  Illustrations 

PAGE 

Fig.  221. — Elements  of  Typical  Cooling  Group,  Defining  Construction  of 

Centrifugal  Pump,  Cooling  Fan  and  Cellular  Cooler  .  .  .  391 

Fig.  222. — Two  Forms  of  Water  Circulating  Pumps  Representing  Current 
Practice.  A — Cooling  Fan  and  Water  Pump  Driven  from  Common 
Source  by  Single  Belt;  Pump  Impeller  Placed  Directly  in  Water- 
jacket.  B — Gear  Circulating  Pump  . 392 

Fig.  223. — Water  Cooling  Group  Used  on  Maxwell  Automobiles  in  which 
Water  Circulation  is  Maintained  by  Natural  Means.  A — Side  View 
of  Power  Plant  Showing  Application  of  Piping.  B — Plan  View  Out- 
lining Disposition  of  Parts 393 

Fig.  224. — Renault  Thermo-Syphon  System,  in  which  Radiator  is  Placed 
in  Back  of  Engine  Instead  of  in  Front,  as  is  Conventional  Practice. 
A — Showing  Method  of  Utilizing  Fan  Fly-wheel  to  Insure  Air  Cir- 
culation Through  Radiator.  B — Plan  View  Depicting  Flow  of  Air 
Currents  through  Cooler  .  .  . 394 

Fig.  225. — Showing  Large  Water  Manifolds  Designed  to  Secure  Positive 

Circulation  by  Thermo-Syphon  or  Natural  Methods  .  .  .  395 

Fig.  226. — Typical  Ball-Bearing  Hub-Cooling  Fan  Designed  to  Create  Air 
Draught  Through  Radiator  and  Around  Cylinders  of  Motor  Car 
Power  Plant 396 

Fig.  227. — Air-Cooling  System  Employed  on  Cameron  Motors  Depends 
upon  Air  Draught  from  Fan  to  Circulate  Around  Flanges  on  Cyl- 
inders and  Absorb  Excess  Heat 397 

Fig.  228.— Parts  of  Air-Cooled  Cylinder  Showing  Method  of  Seating 
Valves  Directly  in  Detachable  Cylinder  Head,  and  Large  Flanges 
on  Both  Cylinder  and  Head  Member  to  Largely  Increase  Effective 
Radiating  Surface 398 

Fig.  229. — Depicting  Section  Through  Lower  Section  of  One  Type  of 
Franklin  Engine,  Showing  Application  of  Auxiliary  Exhaust  Valve 
to  Relieve  Cylinder  of  Flaming  Gases  at  End  of  Power  Stroke  .  400 

Fig.  230. — Two  Forms  of  Positive  Air  Fans  Used  in  Automobile  Cooling 
Systems.  A — Gear-Driven  Three-Blade  Fan  Utilized  to  Draw  Air 
Through  Win-ton  Radiator.  B — Blower  Member  Used  on  Kelly  Air- 
Jacketed  Cylinder  Motor ;  401 

Fig.  231. — Sectional  View  of  Chase  Two-Cycle  Engine,  a  Two-Stroke 
Form  Successfully  Cooled  by  Air  Flanges  Cast  Integral  with  Cyl- 
inder . 402 

Fig.  232. — Positive  Cooling  Method  Used  on  Franklin  Automobiles  in 
which  Air  Currents  are  Drawn  Through  Cylinder  Jackets  by  Fly- 
wheel Fan  Suction 403 

Fig.  233. — Air-Jacketed  Frayer-Miller  Engine  Used  in  Kelly  Trucks 
Cooled  by  Air  Currents  Directed  over  Cylinders  by  Positive  Air- 
Blower  System 404 


List  of  Illustrations  25 

CHAPTER    VIII 

PAGE 

Fig.  234. — Plan  of  Components  of  Power  Transmission  System  of  Typ- 
ical Gasoline  Automobile,  Depicting  Relation  of  Clutches,  Gearset 
and  Driving  Gears 407 

Fig.  235. — Sectional  View  of  Cone  Clutch  Having  Female  Member 

Formed  Integral  with  Fly-wheel  Rim 413 

Fig.  236. — Cone  Clutch  Design  with  Female  Member  a  Separate  Casting 

Bolted  to  Fly-wheel  Rim 415 

Fig.  237. — Typical  Cone  Clutch  Male  Members  Showing  Methods  of  At- 
taching Leather  Facing  to  Cone  Castings.  A — Pope-Hartford  Clutch 
Cone  Faced  with  Leather  and  Cork  Inserts.  B — White  Cone  Uses 
Leather  Band  Held  in  Place  by  T  Bolts 416 

Fig.  238. — Cone  Clutches  of  English  Design.  A — Metal-to-Metal  Surfaces 
in  Oil-tight  Case.  B — Method  of  Holding  Parts  in  Contact  with  Ad- 
justable Springs 417 

Fig.  239. — Columbia  Clutch  Employs  Friction  Shoes  to  Grip  Fly-wheel 
Before  Cone  is  Fully  Engaged,  to  Secure  Gradual  Application  of 
Power 419 

Fig.  240. — Three-Plate  Clutch  Utilized  on  Knox  Motor  Cars  Uses  a  Cen- 
tral Driven  Plate  Studded  with  Cork  Inserts 421 

Fig.  241. — A  Three-Plate  Clutch  Equipped  with  Friction  Brake  to  Arrest 

Motion  of  Driven  Member  when  Clutch  is  Released  ....  422 

Fig.  242. — Five-Plate  Clutch  which  Employs  Two  Driving  Members 

Attached  to  Fly-wheel  and  Three  Driven  Plates  ....  423 

Fig.  243.— Typical  Multiple  Disk  Clutch  Assembly.  The  Form  Illus- 
trated is  Used  on  Some  of  the  Hudson  Cars 426 

Fig.  244. — Multiple  Disk  Clutch  Utilized  on  Franklin  Automobiles  is 
Housed  in  Blower  Fly-wheel.  Parts  are  Shown  Separated  to  Make 
Construction  Clear 427 

Fig.  245.— Clutch  of  Premier  Cars  Uses  Multiple  Disks  Studded  with 
Cork  Inserts  as  Driving  Members,  and  Plain  Metal  Plates  as  Driven 
Elements  .  .  .  . 427 

Fig.  246. — Outlining  Action  of  Simple  Face  Friction  Gearing,  which 

Combines  Clutching  and  Speed  Changing  Functions  .  .  .  430 

Fig.  247. — How  Face  Friction  Gearing  is  Installed  in  Motor  Car  Chassis. 
A — Arranged  for  Shaft  Drive.  B — Power  Transmitted  to  Wheels 
by  Side  Chains  . 432 

Fig.  248. — Disposition  of  Important  Elements  of  Simple  Face  Friction 

Gearing  Adapted  for  Single  Chain  Drive 433 

Fig.  249. — Sectional  View  of  Simple  Planetary  Gearset     .        .        .        .         435 

Fig.  250. — Demonstrating  Action  of  Epicycle  Gearing.  A — The  Slow 
Speed  Gear  Assembly.  B — Gears  and  Pinions  Used  for  Reverse 
Drive  .  436 


26  List  of  Illustrations 

PAGE 

Fig.  251. — Planetary  Gearing  Utilizing  Only  Spur  Gears  Carried  in  Oil- 
tight  Case 437 

Fig.  252. — Two-Speed  and  Keverse  Planetary  Gear  Employed  on  Ford 

Automobiles 438 

Fig.  253. — Part  Sectional  View  of  Cotta  Individual  Clutch  Transmission 

Designed  for  Heavy  Motor  Truck 440 

Fig.  254. — Individual  Clutch  Transmission  Using  Silent  Chain  Connec- 
tion Between  Main  and  Countershafts  for  Forward  Speeds  and  Slid- 
ing Spur  Gears  for  Reverse  Action 441 

Fig.  255. — Sectional  View  of  Individual  Clutch  Gearset  with  Silent 

Chains  Removed  to  Show  Arrangement  of  Gearing  .  .  .  442 

Fig.  256. — Arrangement  of  Gears  in  Progressive  Sliding  Gearset     .        .         444 

Fig.  257. — Showing  Application  of  Two  Shifting  Members  on  Main  Shaft 

of  Selective  Sliding  Gear  Speed  Changing  Mechanism  .  .  445 

Fig.  258. — Comparing  Progressive  and  Selective  Gearset  Action  to  Dem- 
onstrate Advantages  of  the  Latter  Form 446 

Fig.  259.— Three -Speed  Selective  Gearset  in  which  All  Speeds  are  Ob- 
tained by  Gears,  No  Direct  Lock  Being  Provided  for  High  Speed  449 

Fig.  260. — Arrangement  of  Gears  and  Shafts  in  Typical  English  Three- 
Speed  Selective  Gear  Box 450 

Fig.  261.— White  Four- Speed  Gearset  Has  Direct  Drive  on  Highest 

Ratio 450 

Fig.  262.— Winton  Four- Speed  Gearset  Provides  Direct  Drive  on  Third 

Speed  and  Gears  Up  for  Highest  or  Fourth  Speed  Ratio  .  .  451 

Fig.  263. — Conventional  Methods  of  Installing  Gearsets  in  Chassis. 
A — Combined  with  Engine  to  Form  Unit  Power  Plant.  B — Fitted 
as  an  Individual  Unit  Back  of  Engine.  C — Combined  with  Rear 
Axle.  D — Mounted  at  .Front  End  of  Driving  Shaft  Housing  .  452 

Fig.  264. — Clutch  and  Gearset  Portion  of  Unit  Power  Plant  Showing 

Positive  Alignment  Between  Clutch  and  Gearset  Main  Shaft  .  453 

Fig.  265. — Herreshoff  Unit  Power  Plant  Partially  Dismantled  to  Show 

Clutch  and  Gearset  Construction 454 

Fig.  266. — Change  Speed  Gearing  Combined  with  Countershaft  for  Side 

Chain  Drive  . 455 

Fig.  267.— Countershaft  and  Three-Speed  Selective  Slinding  Gearset 
Mounted  as  a  Unit  Insures  Positive  Alignment  of  Speed-Changing 
and  Power-Transmitting  Elements 456 

Fig.  268. — Unconventional  Arrangement  of  Three-Speed  Selective  Sliding 
Gearset  in  Combination  with  Rear  Axle  to  Secure  More  Compact 
Construction  by  Housing  Change  Speed  and  Driving  Gearing  in 
Common  Case 457 

Fig.  269. — Usual  Arrangement  of  Change  Speed  and  Driving  Gearing  at 

Differential  Housing  of  Live  Rear  Axle  or  Countershaft  .  .  458 


List  of  Illustrations  27 

PAGE 

Fig.  270. — Conventional  Gasoline  Automobile  Chassis  Forms.  A — Type 
in  which  Frame  is  Mounted  Over  Axles,  the  Usual  Construction. 
B — Underslung  Chassis,  in  which  Frame  is  Suspended  Beneath 
Axles 460-461 

CHAPTER    IX 

Fig.  271. — Advantage  of  Low  Weight  Placing  and  Carrying  Center  of 
Gravity  Near  the  Ground.  A — Low  Center  of  Gravity  Makes  for 
Stability.  B— High  Center  of  Gravity  Unsafe 461 

Fig.  272. — Conventional  Form  of  Pressed  Steel  Automobile  Frame  with 

Cambered  Side  Members 463 

Fig.  273. — Frame  Forms  Having  Raised  Side  Members.  A — Frame  Side 

Raised  Over  Axle.  B — Framework  with  Drop  Side  Member  .  464 

Fig.  274. — Springs  Usually  Employed  for  Supporting  Motor  Car  Frames 

and  Horse-Drawn  Vehicle  Bodies  .  .  .  .  .  .  .  .  467 

Fig.  275. — Spring  Suspension  Means  for  Front  Ends  of  Motor  Car 
Frames.  A— Semi-elliptic,  B— Full  Elliptic  of  Franklin  Car.  C— 
Single  Cross  Spring  of  Ford  Design 468 

Fig.  276. — Spring  Suspensions  for  Rear  Ends  of  Motor  Car  Chasses. 
A — Single  Elliptic  Cross  Spring  of  Ford  Cars.  B — Semi-elliptic  Side 
Member.  C — Rear  Support  by  Full  Elliptic  Spring.  D — Platform 
Spring  Construction.  E — Three-Quarfer  Elliptic  Application  .  469 

Fig.  277. — Unconventional  Spring  Suspensions.  A — Double  Semi-elliptic 
Used  on  Winton  Cars.  B — Coil  Spring  and  Shock  Absorber  Com- 
bination of  Liberty-Brush  Runabouts 472 

Fig.  278. — Methods  of  Steering  Vehicles  Outlined.  A — Horse-Drawn 
Wagon  Directed  by  Swinging  Axle.  B — Motor  Car  Steered  by  Mov- 
able Wheels  on  Fixed  Axle 474 

Fig.  279. — How  Front  Wheels  of  Motor  Cars  are  Moved.  A — Conven- 
tional Worm-Gear  Reduction  Steering  Arrangement.  B — Simple 
Rack  and  Pinion  System  Used  on  Light  Cars 476 

Fig.  280. — Unconventional  Steering  Gear  Employing  Threaded  Steering 
Post  and  Movable  Nut  with  Rack  to  Engage  Sector  on  Steering  Arm 
Shaft 477 

Fig.  281. — Construction  of  Worm  and  Worm-Gear  Reduction  Gearing  for 

Steering  Purposes *  .  .  .  .  479 

Fig.  282. — Typical  Steering  Post  Assembly  Showing  Hand  Wheel  and 
Motor  Controlling  Levers.  Sectional  View  of  Worm  and  Worm 
Wheel  and  Steering  Arm  Connecting  Member 480 

Fig.  283.— Typical  Front  Axle  Types.  A— Forging  of  I  Section.  B— 

Tubular  Axle 482 

Fig.  284. — Typical  Front  Hub  and  Steering  Knuckle  Designs.  A — Elliot 
Type  Hub  with  Taper  Roller  Bearings.  B — Front  Hub  Mounted  on 


28  List  of  Illustrations 


PA  (IK 


New  Departure  "  Radax  "  Ball  Bearings.  C — Mercedes  Type  Steer- 
ing Knuckle,  Hub  Mounted  on  Single  and  Double  Row  Bearings  .  483 

Fig.  285. — Methods  of  Power  Transmission  Employed  by  Motor  Car  De- 
signers. A — Single-Chain  Drive  from  Planetary  Gearset  to  Live 
Rear  Axle.  B — Side  Chain  System.  C — Drive  by  Exposed  Shaft 
Having  Two  Universal  Joints.  D — Drive  Shaft  Enclosed  in  Torque 
Tube  Needs  but  One  Universal  Joint 485 

Fig.  286. — Chassis  of  Knox  Car,  in  which  Straight-Line  Driving  Shaft  is 
Utilized,  which  Permits  Power  Transmission  with  but  Minimum 
Loss 486 

Fig.  287. — Rear  Axle  Types  Generally  Used.  A — Live  Rear  Axle  Using 
Shafts  which  Transmit  Power  and  also  Carry  Weight,  Equipped 
with  Roller  Bearings.  B — Full  Floating  Type  Bevel  Gear  Drive 
Axle. .  C — Stationary  Axle  with  Chain  Drive  to  Free  Wheels  .  488 

Fig.  288. — Combined  Live  and  Stationary  Axle  which  Combines  Good 
Features  of  Both  Types  and  Eliminates  All  Objections  to  Either. 
The  Strongest  Possible  Construction 489 

Fig.  289. — Illustrating  Differential  Gear  Action  when  Applied  to  Bevel 

Gear  Drive  Axle 491 

Fig.  290. — Bevel  Gear  Drive  Assembly  of  Ford  Light  Cars  Mounted  on 

Hyatt  Flexible  Roller  Bearings  .  • 493 

Fig.  291. — Bevel  Gear  Drive  Assembly  Mounted  on  Timken  Tapered 

Roller  Bearings 494 

Fig.  292. — Worm  Gear  Driving  Assembly  Utilized  on  Pierce  Motor  Trucks 
and  Form  of  Worm  and  Worm  Wheel  Utilized  in  Power  Trans- 
mission . 495 

Fig.  293. — Worm  Gear  Driving  Axle  Used  on  Dennis  (English)  Motor 

Cars 496 

Fig.  294. — Method  of  Enclosing  Driving  Chain  in  Oil-tight  Casing  to 

Secure  Efficient  Driving  and  Long  Life  of  Mechanism  .  .  .  497 

Fig.  295. — Sectional  View  of  Torbensen  Axle  for  Motor  Trucks  which 
Combines  Features  of  Both  "  Live  "  and  "  Dead  "  Rear  Axle  Forms 
and  which  Utilizes  Two  Driving  Gearing  Sets  .  .  .  .  .  498 

Fig.  296. — Live  Rear  Axle  with  Combined  Bevel  and  Spur  Gear  Final 

Drive  ;  .  -  .  .  . 498 

Fig.  297. — Simple  Form  of  Shoe  Brake  Used   on  Horse-Drawn  Vehicles     500 

Fig.  298.— Internal  and  External  Band  Brakes  Used  on  Motor  Car  Wheels     501 

F;g.  299. — Typical  Automobile  Brake  Forms.  A — Two  Internal  Bands. 
B — Double  Expanding  Type.  C — External  and  Internal  Brake 
Combination 502 

Fig.  300.— Typical  Automobile  Brake  Assembly  with  Rear  Wheel  Re- 
moved to  Show  Application  of  Brake  Drum  to  Wheel  and  Internal 
and  External  Bands  on  End  of  Axle 503 

Fig.  301.— Rear  Hub  of  Metz  Car  Showing  Multiple-Disk  Brake   .        .         504 


List  of  Illustrations  29 


PAGE 

Fig.  302.— Types  of  Front  Wheel  Brakes  that  Have  Been  Used  on  British 
Automobiles  Showing  Novel  and  Ingenious  Methods  of  Brake 
Actuation 507 


CHAPTER    X 

Fig.  303. — Wooden  Portions  of  Artillery  Type  Automobile  Wheel        .          510 

Fig.  304. — Complete  Artillery  Wheel  Assembly 511 

Fig.  305. — Wire  Spoke  Automobile  Wheel  Modified  from  Bicycle  Prac- 
tice  514 

Fig.  306.— Steel  Resilient  Wheel  Having  Coil  Springs  Separating  Hub 

and  Rim  Members 515 

Fig.  307. — Spring  Wheels  Designed  to  Provide  a  Resilient  Support  for 

Automobiles  Without  Using  Pneumatic  Tires 516 

Fig.  308. — Comparison  of  Action  of  Pneumatic  and  Solid  Rubber  Tires 

when  Wheel  Rides  Over  Obstacle 518 

Fig.  309. — Outlining  Construction  of  Pneumatic  Automobile  Tire  Fitted 

to  Simple  Clincher  Rim 520 

Fig.  310. — Construction  of  Schrader  Universal  Tire  Valve        .        .        .          521 

Fig.  311. — Forms  of  Quick  Detachable  Rims  which  Permit  Easy  Re- 
moval of  Pneumatic  Tires •  .  .  .  523 

Fig.  312. — Showing  Various  Raised  Treads  Used  on  Pneumatic  Tire  Cas- 
ings .......  J 525 

Fig.  313. — How  Outer  Casing  Treads  May  Be  Formed  to  Secure  Greater 
Tractive  Effort  than  Obtained  from  Smooth  Treads  and  Prevent  Side 
Slipping 527 

Fig.  314. — Supplementary  Treads  and  Anti-Skidding  Attachments  De- 
signed to  Use  in  Connection  with  Smooth-Tread  Casings  .  .  529 

Fig.  315. — Methods  of  Applying  Weed  Chains  to  Tire  without  Jacking 

Up  Wheel 530 

Fig.  316. — Quick  Detachable  Rim  of  the  Demountable  Form        .        .          532 

Fig.  317. — Examples  of  Standard  Demountable  Rims  for  Conventional 

Types  of  Casings  .  . 533 

Fig.  318. — Cushion  Tires  which  Provide  More  Resiliency  than  Solid  Rub- 
ber Types  but  are  Not  Equal  to  the  Pneumatic  Forms  .  .  535 

Fig.  319. — Novel  Forms  of  Cushion  Tires.  A— Cairns  Detachable  Seg- 
ment Construction.  B — Combination  Form  Comprising  Heavy  Tread 
and  Inflatable  Inner  Tube 536 

Fig.  320. — Outlining  Construction  and  Methods  of  Fastening  Solid  Rub- 
ber Tires  to  Wheels 538 

Fig.  321. — Twin  Type  Solid  Tires  for  Heavy  Motor  Trucks  and  Meth- 
ods of  Holding  Members  in  Place  on  Wheels  .  539 

Fig.  322, — Hartford  Detachable  Twin  Solid  Tire  Construction       .        .    '      540 


30  List  of  Illustrations 

PAGE 

Fig.  323. — Spare  Parts  and  Necessary  Repair  Equipment  for  Automo- 
biles Using  Pneumatic  Tires 541 

Fig.  324. — Forms  of  Tire  Irons  Used  in  Removing  and  Repairing  Clincher 

Shoes  .  .  .542 

Fig.  325. — Small  Repair  Kit  Containing  Necessary  Tools  and  Supplies 

for  Emergency  Repairs 543 

Fig.  326. — Tools  Found  Useful  when  Repairing  Inner  Tubes        .        .          544 

Fig.  327. — Portable  Vulcanizer  Outfit  for  Filling  Cuts  in  Outer  Casings 

or  Patching  Inner  Tubes 544 

Fig.  328. — Acid-Cure  Vulcanizing  Outfit 545 

Fig.  329. — Special  Appliance  for  Loosening  Clincher  Shoes  from  Rim  of 

Wheel 54(i 

Fig.  330. — Tools  for  Removing  Fisk  "  Bolted  On  "  Casings  and  Method  of 

Using  Them 548 

Fig.  331. — Adjustable  Iron  for  Loosening  Clincher  Casings  that  Have 
Stuck  to  Rims 

Fig.  332. — Sectional  View  of  Pneumatic  Tire  Showing  Some  Conditions 
which  Cause  Failure 

Fig.  333. — Temporary  Casing  Repairs  Possible  when  Small  Blow-out  or 
Large  Puncture  Occurs  on  the  Road  • 

Fig.  334. — Methods  of  Using  Small  Electric  or  Vapor  Vulcanizers  on 
Tube  and  Casing  Work,  a  Very  Convenient  Method  of  Effecting 
Permanent  Repairs 557 

Fig.  335.— How  Inner  Tubes  May  Be  Pinched  and  Ruptured  if  Outer  Cas- 
ing is  Replaced  Carelessly  or  if  Tire  Lugs  are  Not  Properly  Placed  558 


CHAPTER   XI 

Fig.  336. — Simple  Ignition  Starting  System  Using  Acetylene  Gas  and 
Hand-Operated  Distribution  Valve  on  Dash 

Fig.  337. — Ignition  Starting  System  in  which  a  Hand-Operated  Pump 
Forces  Mixture  to  Cylinders 

Fig.  338. — Never-Miss  Starting  System  with  Special  Air  Motor  for 
Mechanical  Cranking . 

Fig.  339. — Janney-Steinmetz  Compressed  Air  Starting  System 

Fig.  340. — Parts  of  Air  Starting  Group  Supplied  on  Chalmers  Cars.  A — 
Pressure  Supply  Valve.  B — Compressed  Gas  Tank.  C — Dash  Start- 
ing Button.  D — Mechanical  Distributor.  E — Cylinder  Check 
Valves.  F— Gas  Shut-off.  G— Pressure  Gauge  on  Dash.  H  and  I— 
Air  Connection  for  Tire  Inflation 

Fig.  341. — Motor  Generator  Employed  in  Starting  Cadillac  Motor  also 
Furnishes  Current  for  Ignition  and  Lighting  .  .  .  .  . 

Fig.  342. — Gas  Generators  and  Lamps  Used  in  Connection  with  Acetylene 
Headlight  Installation 


List  of  Illustrations  31 

PAGE 

Fig.  343. — Special  Storage  Battery  Employed  to  Furnish  Lighting  Cur- 
rent   573 

Fig.  344. — Side  and  Tail  Lamps  Using  Electric  Bulbs  for  Illumination. 
A — Kerosene  Side  Lamp  with  Tungsten  Lamp  in  Corner.  B — Pillar 
Lamp  for  Limousine  Bodies  Uses  Electric  Lamp  Exclusively,  C— 
Small  Electric  Tail  Lamp 574 

Fig.  345. — A — Side  Lamps  Designed  to  Use  only  Electric  Bulbs.  B — 
Methods  of  Combining  Kerosene  Burner  and  Tungsten  Bulb  in  Side 
Lamps 575 

Fig.  346. — Gray  &  Davis  Combined  Electric  Tail  Lamp  and  License  Plate 

Holder,  a  Device  of  Marked  Utility  . i  576 

Fig.  347. — Incandescent  Bulbs  and  Sockets  Used  in  Motor  Car  Lamps  .         577 

Fig.  348. — Convenient  Electric  Fixtures  that  May  Be  Included  in  Equip- 
ment of  Cars  Using  Electric  Lighting  Systems  .  .  .  .  578 

Fig.  349. — Sectional  View  of  Gray  &  Davis  Electric  Headlight  Showing 

Method  of  Focusing  Bulb  by  Accessible  Adjusting  Screw  .  .  579 

Fig.  350. — Combination  Headlight  Fitted  with  Both  Gas  Burner  and 
Electric  Bulb.  A— Position  of  Bulb  with  Gas  Flame  in  Use.  B— 
Bulb  Furnishing  Light 580 

Fig.  351. — Wiring  Diagram  Showing  Connections  of  Simple  Three-Lamp 

Electric  Lighting  System  . 581 

Fig.  352.— Complete  Six-Lamp,  Three-Circuit  Electric  Lighting  System 

with  Mechanical  and  Chemical  Current  ..Producers  ....  583 

Fig.  353. — Conventional  Wind  Shield  Forms 584 

Fig.  354. — Methods  of  Promoting  Easy  Riding  of  Automobiles  Supplied 

with  Inadequate  Springs 586 

Fig.  355. — Efficient  Shock  Absorbers  that  Improve  Spring  Action  on 
Rough  Roads.  A— Truffault-Hartford  with  Friction  Pad.  B— Con- 
necticut Device  Moves  Cam  Against  Spring  Resistance  .  .  .  587 

Fig.  356. — Forms  of  Motor  Car  Alarms  that  Give  Satisfactory  Service. 
A — Combined  Klaxon  Signal  and  Bulb  Horn.  B  and  C — Exhaust 
Whistles.  D— Electrically  Operated  Signal 588 

Fig.  357. — Speedometers  Useful  in  Indicating  Speed  and  Mileage    .        .         589 

Fig.  358. — Sectional  View  of  Speedometer  which  Depends  on  Centrifugal 

Force  Stored  in  Governor  Weights  to  Actuate  Indicating  Needle  .  590 

Fig.  359. — Tool  Roll  Suitable  for  Making  All  Ordinary  Repairs  on  Auto- 
mobile Mechanism 593 

Fig.  360.— Useful  Tools  that  May  Be  Furnished  to  Supplement  Contents 

of  Tool  Rolls  or  Ordinary  Small  Tool  Outfits 595 

Fig.  361.— Group  of  Supplies  that  Will  Be  Found  Useful  when  Touring 

or  in  Maintaining  Motor  Cars 598 

Fig.  362. — Leading  Types  of  Car-Raising  Jacks     .        .        .        .        .        .         602 

Fig.  363. — Some  Conventional  Methods  of  Storing  Supplies  and  Equip- 
ment 604 


32  List  of  Illustrations 

PAGE 

Fig.  364. — How  Two  Leading  Motor  Car  Manufacturers  Make  Provision 

for  Carrying  Spare  Tires  and  Other  Supplies 605 

Fig.  365. — Side  Elevation  and  Plan  View  of  Modern  Motor  Car  Showing 
Disposition  of  Various  Articles  of  Equipment  without  Hampering 
Passengers  or  Reducing  Carrying  Capacity 606 

CHAPTER   XII 

Fig.  366.— Parts  of  Motor  Control  System  of  Peerless  Car.  Spark  Ad- 
vance Regulated  by  Small  Hand  Lever.  Gas  Supply  Controlled  by 
Automatic  Engine  Governor,  Accelerator  Pedal  or  Throttle  Lever 
on  Steering  Wheel 609 

Fig.  367. — Position  of  Spark  and  Throttle  Control  Levers  on  Cadillac  Car 

to  Obtain  Various  Car  Speeds  with  Gearing  in  Direct  Drive  .  .  613 

Fig.  368. — Control  System  of  Carter  Car,  which  Employs  Friction  Trans- 
mission   615 

Fig.  369. — Simple  Speed-Regulation  Method  on  Maxwell  Cars  Furnished 

with  Planetary  Gearsets 617 

Fig.  369A. — Outlining  the  Distinctive  Control  System  of  Ford  Model 
"  T  "  Automobile,  which  Employs  Two  Speed  and  Reverse  Planetary 
Gearing.  Location  of  Spark  and  Throttle  Levers  Clearly  Shown  in 
Inset  .  ....  . •'.•••.-.  619 

Fig.  370. — Selective  Change  Speed  System  of  Liberty-Brush  Light  Runa- 
bout   621 

Fig.  371. — Side  Control  Levers  and  Pedals  of  Pierce- Arrow  Sliding-Gear 

Cars 622 

Fig.  372. — Complete  Control  System  of  Buick  Automobiles  Showing  En- 
gine Regulating  Levers  on  Steering  Wheel,  Enclosed  Hand  Levers 
and  Foot  Control  of  Clutch  and  Running  Brake  ....  624 

Fig.  373. — Change  Speed  Gates  for  Three  and  Four  Speed  Selective  Trans- 
missions '-..  . 625 

Fig.  374.— Control  System  with  Single  Centrally  Located  Gear  Shift 

Lever  and  Steering  Wheel  on  Left  Side 626 

Chart  Showing  Action  of  Selective  Sliding  Gearset   .        .        .        .         626-627 

Fig.  375. — Speed  Change  Levers  of  Knox  Cars •      .         628 

Fig.  376.— Complete  Control  Group  of  Mitchell  Motor  Cars     .        .       .         629 

Fig.  377. — Center  Control  Levers  of  Jackson  Cars  and  Pedals  for  Clutch 

Running  Brake,  Accelerator  and  Muffler  Cut-out  Operation  .  .  630 

Fig.  378. — Comprehensive  Lubrication  Chart  Furnished  by  Manufactur- 
ers of  Thomas  Automobiles  for  Guidance  of  Owners  Insures  Ade- 
quate Lubrication  of  All  Essential  Parts  of  the  Mechanism  at 
Regular  Periods  .........  632-633 

Fig.  379. — Two  Methods  of  Obtaining  Gasoline  from  Container  to  Prime 

Cylinders  and  Facilitate  Motor  Starting  in  Cold  Weather  .  .  638 


List  of  Illustrations  33 

PAGE 

Fig.  880. — Special  Cover  to  Protect  Radiator  During  Cold  Weather  and 
Prevent  Freezing  Cooling  Water.  A — Slots  Open  for  Air  Passage 
While  Car  is  Used.  B — Radiator  Completely  Protected  when  En- 
gine is  Stopped.  Cover  Retains  Heat  and  Makes  for  Easy  Re- 
starting   639 

CHAPTER    XIII 

Chart  Showing  Common  Troubles  Causing  Defective  Operation  of  Unit 

Power   Plant  653 


GENERAL   INTRODUCTION 

THE  modern  motor  car  has  reached  that  period  in  its  development 
where  one  can  safely  say  that  it  has  become  perfected  to  such  an  ex- 
tent that  further  improvements  must  be  in  matters  of  detail  only  and 
not  in  alterations  of  essential  components.  It  has  been  so  widely 
adopted  and  is  used  in  so  many  industrial  applications  that  even  the 
most  conservative  must  admit  the  automobile  has  ceased  to  be  an  ex- 
periment and  it  is  a  reliable  method  of  transportation  that  has  dem- 
onstrated its  worth  conclusively. 

It  is  said  that  there  are  over  800,000  motor  vehicles  in  use  in  the 
leading  countries  of  the  world,  and  the  yearly  output  of  the  world's 
manufactures  is  approximated  at  about  300,000  cars  per  annum.  Of 
this  number  over  500,000  power-propelled  vehicles  are  used  in  the 
United  States,  and  the  yearly  output  of  domestic  producers  is  esti- 
mated at  190,000  automobiles.  The  enormous  demand  existing  for 
this  practical  conveyance  has  impelled  the  manufacture  of  well-devel- 
oped types  of  motor  cars  which  can  be  sold  at  very  moderate  prices 
because  they  are  produced  in  large  numbers.  This  has  resulted  in 
a  wide  increase  in'  the  number  of  motorists  and  many  who  formerly 
could  not  afford  the  higher  priced  automobiles  have  become  motor 
car  operators  because  they  can  maintain  the  moderate  priced  cars  at 
present  obtainable  without  too  great  expense. 

Obviously,  it  is  not  difficult  to  acquire  a  knowledge  of  the  princi- 
ples of  operation  or  the  mechanism  of  the  conventional  motor  car  if 
one  has  had  mechanical  training  or  a  practical  knowledge  of  automo- 
bile construction,  and  it  is  patent  that  many  motorists  who  are  driv- 
ing their  own  cars  have  but  a  vague  understanding  of  the  principles 
of  operation  of  the  mechanism  which  comprises  the  up-to-date  auto- 
mobile. The  ranks  of  motorists  might -be  augmented  by  many  who 
have  the  means  to  purchase  but  who  believe  that  the  maintenance 
cost  would  exceed  that  of  a  horse-drawn  conveyance  of  equal  capacity, 
and  the  natural  impression  which  prevails  that  only  those  well  versed 

35 


36  General  Introduction 

mechanically  can  operate  motor  cars  successfully  can  be  dispelled  only 
by  a  better  understanding  of  motor  car  construction.  When  one  takes 
cognizance  of  the  many  vehicles  successfully  operated  by  compara- 
tively inexperienced  persons  it  is  apparent  that  operating  is  not  diffi- 
cult, but  it  is  the  repairing  and  maintenance  costs  that  deter  many 
from  owning  motor  cars. 

There  has  been  no  lack  of  instruction  books  or  elementary  treatise 
dealing  with  motor  vehicle  construction,  maintenance  or  operation, 
but  in  these,  for  the  most  part,  a  common  error  has  been  made  of 
assuming  that  the  reader  had  more  or  less  knowledge  of  mechanics.  It 
is  evident  that  any  work  which  presupposes  a  certain  amount  of  train- 
ing on  the  part  of  the  reader  cannot  be  successfully  employed  in  teach- 
ing the  rudiments  of  any  science.  At  the  other  hand,  pamphlets 
which  are  too  elementary  in  character  cannot  convey  a  practical  work- 
ing knowledge  because  so  much  is  left  for  the  motorist  to  learn  after 
he  has  grasped  the  main  principles  underlying  the  design.  Many 
business  or  professional  men  do  not  possess  even  an  elementary  knowl- 
edge of  mechanical  principles,  and  as  this  class  forms  the  largest 
proportion  of  the  motoring  element,  in  denning  the  basic  principles 
of  an  automobile,  it  is  necessary  to  use  simple  exposition  that  often- 
times appears  to  be  elementary  to  the  student  or  engineer  well  versed 
in  the  subject  under  discussion. 

Many  of  the  works  on  automobile  construction  which  have  been 
exceptionally  valuable  in  the  past  have  a  materially  lessened  value 
because  much  of  the  matter  contained  therein  is  out  of  date  and  not 
applicable  to  the  vehicles  of  the  present  day.  In  the  present  work 
the  writer  will  endeavor  to  define  the  essential  elements  of  the  modern 
gasoline  motor  car,  and  after  explaining  the  basic  principles  upon 
which  the  successful  use  depends,  it  is  proposed  to  describe  actual 
forms  and  typical  mechanisms  so  that  their  practical  application  and 
the  relation  the  various  parts  bear  to  each  other  can  be  easily  under- 
stood. It  is  obvious  that  familiarity  with  the  machinery  of  an  auto- 
mobile will  enable  the  operator  to  give  intelligent  attention  which  will 
insure  the  longest  life  and  minimum  operating  expense. 

It  is  believed  that  a  systematic  and  logical  arrangement  of  the 
subject  will  enable  the  reader  to  gain  an  understanding  of  the  func- 
tions of  each  part  and  the  typical  groups  of  mechanism  illustrated 


General  Introduction  37 

and  described  should  make  for  a  better  understanding  of  the  various 
parts  as  they  actually  are  in  the  leading  automobiles.  While  it  has 
been  the  practice  in  works  of  this  character  to  include  a  general  expo- 
sition of  all  types  of  self-propelled  conveyances,,  including  gasoline, 
steam,  and  electric  automobiles,  in  the  present  instance,  matter  re- 
lating to  the  steam  or  electric  motor  car  will  not  be  given.  The  writer 
will  discuss  only  those  automobiles  in  which  the  gasoline  engine  or 
hydro-carbon  motor  is  utilized  as  a  prime  mover. 

The  gasoline  car  is  now  used  almost  universally,  and  the  steam 
vehicle  or  conveyance  propelled  by  electric  power  has  been  practically 
relegated  to  the  background.  The  gasoline  car  has  such  obvious 
advantages  and  is  so  economical  to  maintain  that  when  a  proper  analy- 
sis of  its  good  features  is  made,  the  reason  for  its  popularity  will  be 
apparent.  Among  many  of  the  advantages  of  the  gasoline  car  may 
be  mentioned  first — the  large  range  of  choice  because  of  the  number 
of  types  available  on  the  market.  Second — the  capability  of  running 
long  distances  without  replenishing  supplies.  Third — wide  dissemi- 
nation of  knowledge  regarding  its  construction.  Fourth — no  gauges 
to  watch  and  practically  automatic  operation.  Disadvantages  some- 
times cited  are  an  occasional  unpleasant  exhaust,  the  necessity  for 
physical  starting  of  the  engine  (at  the  present  time  largely  eliminated 
by  self -starting  mechanisms),  and  shifting  change  speed  gearing  when 
road  conditions  or  gradients  demand  maximum  engine  power. 

The  steam  car  still  has  a  number  of  staunch  adherents  because  it 
possesses  important  advantages  in  that  it  has  a  good  range  of  power 
which  can  be  easily  controlled,  it  is  quiet  in  action,  has  freedom  from 
vibration  and  simple  means  for  control  and  easy  restarting  after  a 
temporary  stop.  Some  of  the  factors  which  militate  against  its  use 
are  a  limited  number  of  makes  to  select  from,  attention  and  time 
required  to  get  the  vehicle  started  after  a  stop  of  some  moment,  close 
attention  required  to  steam,  air,  water,  and  other  indicators,  and  on 
cold  or  damp  days  a  visible  exhaust  due  to  the  condensation  of  the 
used  steam  discharged  from  the  engine. 

The  electric  car  has  many  good  features,  and  it  is  widely  used  for 
both  pleasure  and  business  purposes  wherever  proper  charging  facili- 
ties are  available.  It  is  quiet,  clean,  easily  started  and  controlled,  runs 
with  no  appreciable  vibration,  and  has  very  simple  and  efficient  gear- 


38  General  Introduction 

ing.  The  disadvantages,  however,  counterbalance  the  good  points. 
Such  vehicles  are  expensive  to  operate,  owing  to  the  great  weight  to 
be  driven.  Their  touring  radius  is  limited,  the  average  being  from 
twenty  to  fifty  miles  per  charge  of  batteries.  Other  factors  are  the 
great  weight  to  horse  power  ratio  due  to  the  use  of  storage  batteries; 
the  time  taken  to  recharge;  the  liability  of  batteries  to  injury,  a 
high  initial  and  maintenance  cost  and  slow  speed.  It  is  apparent 
that  its  chief  field  of  activity  would  be  in  towns  or  cities,  delivering 
merchandise,  making  professional  or  social  calls,  attending  theaters, 
shopping,  and  other  strictly  urban  work.  Obviously,  it  cannot  be 
used  for  touring  purposes,  but  where  cost  is  not  an  all-important  ele- 
ment one  will  find  the  electric  automobile  entirely  suitable  and  prac- 
tical for  all  town  work. 

The  writer  believes  that  neither  the  steam  nor  electric  automobile  is 
of  sufficient  moment  at  the  present  time,  when  compared  to  the  num- 
ber of  gasoline  automobiles  in  use,  to  warrant  an  extended  discussion 
of  their  construction  or  operation.  In  the  present  volume  the  space 
which  in  contemporary  works  is  usually  devoted  to  these  types  will 
be  utilized  in  a  practical  discussion  of  items  which  are  usually  neg- 
lected, such  as  gas  engine  operation,  maintenance  and  repair;  hints 
relating  to  tire  restoration  or  manipulation  and  an  exposition  of  the 
latest  and  most  suitable  accessories  which  conduce  to  greater  safety 
or  comfort  while  motoring. 

The  omission  of  the  historical  matter  which  usually  prefaces  a 
work  of  this  character  may  be  criticized  as  well  as  the  elimination  of 
many  machine  details  that  are  commonly  presented  chiefly  because 
of  their  value  in  showing  progress  made.  As  the  science  of  automo- 
bile engineering  has  reached  that  point  where  radical  departures  from 
the  conventional  or  standard  construction  are  not  considered  with 
favor,  it  is  safe  to  assume  that  the  era  of  standardization  and  stability 
of  design  is  at  hand.  Many  changes  have  been  made  in  the  past  in 
basic  design  of  vehicles  or  their  components,  and  many  parts  formerly 
thought  essential  can  be  dispensed  with.  As  an  example  of  the  dis- 
carding of  designs  which  gave  promise  of  being  permanent,  one  may 
mention  the  practical  elimination  of  the  high-wheeled  or  buggy-type 
automobile,  which  are  now  almost  entirely  off  the  market. 

One-3  two-,  and  three-cylinder  four-cycle  engines  and  those  of  the 


General  Introduction  39 

compound  form  or  having  horizontal  cylinders  have  been  displaced 
by  the  modern  four  and  six  vertical  cylinder  forms,  the  former  being 
used  even  in  the  cheapest  types  which  formerly  utilized  one  or  two 
cylinder  power  plants.  Simple  air-cooling  systems  are  seldom  used, 
and  angle  iron  or  wood  frames  which  were  supplied  on  many  pleas- 
ure cars  are  now  used  solely  on  heavy  commercial  vehicles  and  pressed 
steel  frames  are  now  almost  universally  used  in  pleasure  cars.  Plain 
bearings,  used  in  the  past  in  gear  sets  and  axles,  have  been  replaced 
by  anti-friction  members.  Lever,  tiller  or  rack  and  pinion  steering 
gears  are  seldom  used  now,  irreversible  wheel  types  are  employed  on 
nearly  all  classes  of  cars  except  some  electric  runabouts.  The  single 
chain  drive  is  seldom  seen,  while  the  double  chain  system  of  power 
transmission  which  had  wide  application  in  pleasure  cars  has  been 
succeeded  by  more  efficient  driving  systems  and  is  used  only  in  heavy 
commercial  car  work  by  modern  engineers. 

Low  tension  ignition  and  the  use  of  batteries  for  electric  current 
production  are  found  only  on  old  type  cars.  All  modern  vehicles  in- 
clude mechanical  generators  of  electricity  such  as  the  magneto,  or 
dynamo.  Two-cycle  engines  are  not  widely  used  except  in  marine  ap- 
plications. Short  stroke  high-speed  motors  have  been  replaced  by  the 
more  efficient  and  enduring  modern  moderate  speed  forms.  Expand- 
ing band  clutches  which  had  a  number  of  advocates  in  the  past  are 
seldom  used  at  the  present  time.  But  few  makers  use  planetary  or 
individual  clutch  transmissions,  and  two  speed  gearsets  are  seldom 
seen  except  when  an  epicyclic  change  speed  gear  is  fitted. 

The  progressive  sliding  gear  type  is  passe,  and  the  friction  trans- 
missions which  were  formerly  employed  in  many  forms  are  now  util- 
ized only  in  the  simplest  design  on  a  few  cars.  It  was  formerly  con- 
sidered good  practice  to  use  engines  fitted  with  automatic  speed  gov- 
ernors as  automobile  power  plants,  but  governed  engines  are  now 
found  mainly  on  motor  trucks.  Wick,  surface,  drip,  bubbling,  film  or 
generator  valve  type  carburetors  or  vaporizers  have  been  entirely 
replaced  by  the  float  feed  spraying  type.  Among  some  of  the  other 
features  of  construction  which  are  in  decline  may  be  mentioned  tubu- 
lar front  axles,  semi-elliptic  rear  springs  or  long  side  springs  and 
driving  axles  without  torque  or  radius  members. 

On  the  other  hand,  during  the  past  year  there  have  been  a  number 


40  General  Introduction  ' 

of  innovations  which  merit  detailed  description  because  they  are  found 
on  many  automobiles  of  late  models.  Other  works  dealing  with  auto- 
mobile construction  published  in  the  past,  make  no  reference  to  these 
improvements  owing  to  their  recent  development.  Among  these  may 
be  mentioned  torpedo  and  other  symmetrical  body  forms  designed  to 
overcome  air  resistance ;  sleeve  valve  motors,  a  general  adoption  of  the 
selective  sliding  gearset  in  the  three  and  four  speed  forms,  the  adop- 
tion of  shaft  and  bevel  gear  drive  on  even  the  heaviest  pleasure  vehi- 
cles, the  increasing  tendency  to  favor  worm  gear  power  transmission, 
the  universal  application  of  magneto  ignition  and  development  of 
electric  lighting  systems. 

There  is  also  more  consideration  of  left  hand  control,  growing  use 
of  unit  power  plants,  wider  application  of  block  motors  and  two  bear- 
ing crank  shafts,  and  a  better  appreciation  of  the  advantages  of  the 
underslung  chassis.  The  I-beam  section  front  axle  is  almost  univer- 
sally used,  and  there  is  marked  improvement  in  multiple  disc  clutches, 
wider  application  of  practical  self-starters,  and  more  general  adoption 
of  ball  and  roller  bearings  at  all  points.  The  use  of  long  stroke 
motors,  offset  cylinders  and  automatic  lubrication  systems  make  for 
pronounced  increase  in  automobile  efficiency.  There  is  also  an  aug- 
menting tendency  to  place  "change  speed  gearing  on  the  rear  axle, 
toward  the  use  of  three-quarter  springs  for  rear  suspension,  supplying 
larger  wheels  and  tires  as  well  as  quick  detachable  wheels  and  rims. 
Some  of  the  foreign  tendencies  which  may  influence  domestic  design 
are  a  return  to  wire  wheels  by  some  of  the  leading  European  engi- 
neers ;  the  application  of  silent  chains  for  valve  operation,  in  change 
speed  gearing  and  even  final  drive  and  use  of  front  wheel  brakes. 

In  addition  to  these  final  improvements  may  be  added  a  better 
realization  of  the.  advantages  of  alloy  steels,  a  universal  tendency  to 
weight  reduction,  and  increase  of  power  to  weight  ratio.  The  floating 
rear  axle  has  almost  entirely  displaced  the  simpler  form  and  marked 
improvement  is  noticed  in  carburetor  construction  owing  to  changes 
in  grade  of  fuel  now  supplied  which  impelled  the  development  of 
multiple  jet  and  compensating  vaporizer  forms.  Many  novel  and 
practical  accessories  have  also  been  developed. 

In  order  to  make  this  work  wide  in  scope,  not  only  will  principles 
of  construction  and  operation  be  discussed  comprehensively,  but  many 


General  Introduction  41 

examples  from  contemporary  foreign  and  domestic  practice  will  be 
given  to  amplify  the  subject  and  increase  the  reader's  opportunity  for 
the  acquirement  .of  a  practical  motoring  education.  The  illustrations 
have  been  carefully  prepared,  and  for  the  most  part  the  cuts  detailing 
construction  of  the  various  components  are  reproduced  or  adapted 
from  actual  working  drawings  and  thus  are  true  outline  representa- 
tions of  the  objects  described.  As  previously  stated,  it  is  believed 
that  a  concentration  of  effort  in  treating  exclusively  of  vehicles 
propelled  by  internal  combustion  motors  will  make  this  treatise 
one  of  more  practical  value  to  the  majority  of  motorists  than  any 
heretofore  published. 

The  repair  hints  and  suggestions  given  for  maintenance  and 
equipment  are  based  on  a  wide  practical  experience  which  dates  since 
the  inception  of  the  industry  as  a  designer,  repairer,  and  operator  of 
motor  vehicles,  and  should  be  of  exceptional  value  to  those  who  have 
not  had  an  opportunity  to  become  familiar  with  automobiles  but  who 
can  apply  the  experience  of  others  to  good  advantage. 

THE  AUTHOR. 


THE 

MODERN  GASOLINE  AUTOMOBILE 


CHAPTER  I 

Defining  Trend  of  Modern  Practice — Explaining  Important  Components  of  the 
Motor  Car  and  Considering  Functions  of  Each  Group  of  Mechanism. 

DURING  the  past  decade  great  progress  has  been  made  in  all 
branches  of  engineering  and  science.  This  is  especially  true  in  me- 
chanics, and  one  of  the  most  notable  achievements  has  been  the 
advancement  of  the  self-propelled  vehicle  from  a  crude  and  unsatis- 
factory construction  to  one  of  great  refinement  and  practicability.  In 
ten  years  the  growth  of  the  automobile  industry  stands  unparalleled 
in  the  industrial  history  of  the  world.  One  familiar  with  the  im- 
provement of  the  motor  conveyance  during  that  time  and  who  remem- 
bers the  early  types  marvels  at  the  refinement  of  detail  and  the 
changes  in  design  which  exist  in  the  vehicles  of  the  present  day.  The 
modern  gasoline  automobile  fills  every  need  as  it  is  comparatively 
light,  powerful  enough  for  all  road  conditions,  easily  controlled  and 
capable  of  running  for  thousands  of  miles  without  adjustment  of  the 
mechanism.  It  surpasses  the  powerful  locomotive  in  speed  and  relia- 
bility, and  has  a  radius  of  travel  greater  than  any  other  conveyance. 

There  are  numerous  standard  principles  upon  which  motor-car 
construction  is  based,  and  some  of  these  differ  from  each  other  radi- 
cally, both  in  theory  and  practice.  Many  constructions,  if  looked 
at  from  a  purely  academic  point  of  view,  will  appear  to  possess  advan- 
tages which  cannot  be  questioned,  though  on  further  consideration 
a  car  of  apparently  inferior  design  which  does  not  have  the  same 
method  of  accomplishing  a  like  object  may  be  a  better  seller  and  a 
more  popular  car  among  motorists. 

The  tendency  of  the  motor-car  designer  of  the  present  day  is 
toward  simplicity  and  increasing  efficiency  of  the  mechanism.  There 

43 


44  The  Modern  Gasoline  Automobile 

are  many  rules  of  practice  leading  to  this  end  generally  known  to 
engineers,  though  not  accepted  by  all  as  the  best  methods  of  construc- 
tion for  motor  vehicles.  It  is  the  writer's  purpose  to  review  all  the 
types  of  the  various  automobile  components  that  have  merit,  and 
the  qualities  of  each  design  will  be  given  as  stated  by  those  favoring 
it.  This  is  not  intended  as  a  criticism,  but  to  enable  the  motorist 
not  informed  regarding  details  of  motor-car  building  to  make  intelli- 
gent comparison  with  other  forms. 

Within  the  last  few  years  the  design  of  automobiles  has  been  con- 
siderably changed,  and  the  difficulties  that  previously  retarded  devel- 
opment have  been  for  the  most  part  eliminated  by  modern  automobile 
engineers.  This  gradual  modification  of  the  automobile  from  a  crude 
mechanism  to  a  practical  product  has  been  attained  without  radical 
changes  that  many  confidently  forecasted  at  the  inception  of  the  in- 
dustry. The  essential  elements  of  the  motor  car  of  to-day  remain 
practically  the  same  as  far  as  basic  principles  of  design  are  concerned, 
as  those  which  formed  the  basis  of  the  first  motor  car.  Only  the 
details  have  been  changed  and  the  forms  which  have  resulted  from 
the  gradual  process  of  evolution  show  a  steady  tendency  toward  uni- 
formity of  design. 

Important  Components  of  Modern  Motor  Cars. — In  this  era  of 
progress,  one  would  hesitate  to  assert  that  the  motor  car  had  been 
perfected  or  that  it  had  reached  a  finality  in  design,  though  the  expe- 
rience of  the  last  few  years  would  justify  one  in  assuming  that  the 
principles  of  construction  now  applied  so  successfully  may  reasonably 
be  considered  permanent.  The  elements  which  have  been  proven 
essential  to  insure  successful  operation  of  all  self-propelled  convey- 
ances may  be  easily  defined  as  follows : 

First:  The  endeavor  of  modern  constructors  is  to  make  all  oper- 
ating parts  of  such  material,  size,  and  strength,  that  the  severe  strains 
imposed  by  the  rough  nature  of  the  average  road  surface  will  be  re- 
sisted adequately  and  to  secure  endurance  and  serviceability  under 
all  possible  conditions  of  operation. 

Second:  The  mechanism  should  be  as  simple  as  it  is  possible  to 
make  it,  as  this  promotes  ease  of  repairing,  facility  in  handling,  and 
lessens  the  liability  of  trouble  by  reducing  complications.  The  parts 
should  be  in  proper  proportion  and  arranged  in  such  a  manner  rela- 


The  Modern  Gasoline  Automobile  45 

tive  to  each  other  that  one  may  be  removed  or  replaced  without  dis- 
turbing other  correlated  appliances. 

Third:  The  power  furnished  by  the  gasoline  motor  carried  in  the 
frame  must  be  transmitted  to  the  traction  wheels  or  to  the  revolving 
shafts  to  which  they  are  fastened  with  as  little  friction  and  power 
loss  as  is  possible. 

Fourth:  The  two  driven  wheels  (preferably  the  rear  ones)  must 
be  connected  to  some  form  of  compensating  or  balance  gear  which 
enables  each  wheel  to  revolve  independently  of  the  other  at  times 
and  at  different  velocities,  because  in  turning  corners  the  outer  wheel 
describes  a  larger  arc  and  consequently  a  longer  path  than  the  inner 
member.  The  differential  gear  was  one  of  the  most  important  ele- 
ments which  made  for  the  successful  development  of  the  auto- 
mobile. 

Fifth:  The  steering  should  be  done  by  the  two  front  wheels  which 
are  carried  at  the  ends  of  a  yoke  axle  which  is  securely  fastened  to  the 
chassis  frame  by  means  of  the  springs.  The  wheels  are  carried  on 
steering  knuckles  which  must  be  arranged  to  assume  different  angles 
when  the  vehicle  is  turning  corners  oj;  deviates  from  a  straight  path 
in  order  to  secure  positive  steering. 

Sixth:  Springs  must  be  provided,  which  will  have  sufficient 
strength  and  elasticity  to  neutralize  vibration  and  allow  for  uneven- 
ness  of  the  road  surface  by  their  yielding  qualities  and  thus  reduce 
body  movement.  In  order  to  relieve  the  machinery,  running  gear  and 
passengers  of  the  inevitable  vibration  which  obtains  at  even  moderate 
speed  on  ordinary  roads  the  wheels  should  be  provided  with  very 
resilient  tires,  preferably  of  the  pneumatic  or  inflated  forms  for 
pleasure  cars,  and  cushion  or  solid  rubber  on  the  heavier  and  slower 
moving  motor  trucks. 

Seventh:  The  gas  supply  to  the  motor,  the  ignition  of  the  charge, 
and  the  continuation  of  the  engine  cycle  of  operations  should  be  auto- 
matic and  require  no  attention  from  the  operator  after  the  motor  is 
once  started.  To  secure  continued  operation,  mechanical  means  must 
be  provided  for  constant  lubrication  of  all  moving  parts.  All  com- 
ponents which  have  movement  relative  to  other  parts  should  move 
with  as  little  power  loss  by  friction  as  possible,  in  order  to  conserve 
the  available  motor  energy  for  tractive  purposes.  Anti-friction  bear- 


46  The  Modern  Gasoline  Automobile 

ings  of  the  ball  or  roller  type  should  be  employed  on  all  rotating 
shafts  in  the  power  plant,  transmission  system,  and  in  the  wheels  to 
save  power. 

Eighth:  The  center  of  gravity  must  be  carried  relatively  low, 
which  involves  placing  the  body  as  close  to  the  ground  as  practical 
considerations  will  permit.  The  wheel  base,  which  is  the  distance 
between  front  and  rear  wheel  centers,  should  be  long,  in  order  to 
secure  the  best  result  in  tractive  effort,  steering,  and  comfortable 
riding.  The  power  plant  and  other  essential  mechanism  should  be 
carried  on  a  frame  which  will  be  supported  in  such  a  manner  that 
road  shocks  will  not  be  transmitted  to  them  and  so  coupled  together 
that  no  frame  distortion  will  produce  disalignment  of  the  driving 
shafts. 

Ninth:  The  control  elements  must  be  designed  with  a  view  to 
easy  handling.  This  means  that  the  steering  gear  should  be  irre- 
versible— i.  e.,  the  hand  wheel  should  not  be  affected  by  side  movement 
of  the  front  wheels,  thus  relieving  the  driver's  arms  of  all  undue 
strain  while  driving.  Motor  regulation  should  be  by  levers  placed 
convenient  to  the  driver's  hands  or  feet,  and  gear  shifting  should  be 
accomplished  without  difficulty.  Powerful  brakes  must  be  employed 
to  insure  positive  check  of  vehicle  motion  whenever  it  is  desired  to 
bring  the  conveyance  to  a  stop.  It  is  evident  that  the  levers  through 
which  the  brakes  are  operated  should  be  so  proportioned  that  a  mini- 
mum of  effort  on  the  part  of  the  operator  will  serve  to  check  the 
vehicle  immediately. 

Division  of  Motor-Car  Mechanism  in  Groups. — In  order  to  deal  sys- 
tematically with  the  subject  of  motor-car  construction,  one  may 
divide  the  essential  mechanism  into  groups  and  treat  each  of  these 
assemblies  in  detail.  In  order  to  understand  the  functions  of  the 
various  parts,  views  of  typical  pleasure  and  commercial  car  chassis, 
with  all  components  clearly  indicated  are  presented  in  Figs.  1  to  7. 
These  show  conventional  arrangements  of  parts  in  vehicles  which  are 
adapted  to  a  wide  range  or  work.  Of  the  many  elements  comprising 
the  automobile,  the  source  of  power  is  the  most  important.  Then 
comes  the  method  of  power  transmission,  and  last  the  various  chassis 
parts  which  have  to  do  with  suspension,  control,  etc. 

By  referring  to  illustrations,  which  show  the  construction  of  typi- 


The  Modern  Gasoline  Automobile  47 

cal  gasoline  car  chassis  so  clearly,  the  functions  of  the  various  parts 
and  their  relation  may  be  easily  understood.  The  basis  of  any  con- 
veyance, whether  animal  drawn  or  power  propelled,  is  a  running  gear. 
This  consists  of  a  frame  supported  on  springs  which  rest  on  the  axles, 
which  in  turn  carry  the  wheels  on  which  the  whole  assembly  can  roll 
over  the  ground.  In  the  horse-drawn  carriage  where  there  is  no 
necessity  for  a  heavy  or  strong  supporting  frame,  because  of  the  light 
weight  of  the  body  it  is  possible  to  attach  the  springs  directly  to  the 
sills  on  which  the  body  rests.  In  a  motor  vehicle,  however,  the  frame 
is  usually  separate  from  the  carriage  work,  because  it  is  often  necessary 
to  remove  the  body  to  gain  access  to  some  portion  of  the  mechanism 
which  may  need  attention.  The  frame  of  an  automobile  must  be 
strong,  because  the  engine  and  parts  of  the  transmission  system  are 
installed  thereon,  and  also  because  the  speed  possibilities  of  the  auto- 
mobile make  it  necessary  that  the  frame  be  of  sufficient  strength  to 
resist  the  stresses  due  to  car  movement  when  driven  over  uneven  road 
surfaces.  These  strains  are  not  present  in  other  forms  of  conveyances. 
The  locomotive  which  is  capable  of  high  speed  and  which  is  very 
heavy,  travels  on  a  smooth  track,  while  ordinary  horse-drawn  car- 
riages are  not  affected  materially  by 'the  roughness  of  the  path  on 
which  they  travel  because  of  their  low  speed  and  light  weight.  In 
the  frame,  or  chassis  group,  one  may  include  the  main  frame,  sub- 
frame,  steering  gear,  clutch  and  brake  pedals,  hand  levers  for  varying 
change  speed  gear  ratios,  and  applying  emergency  brakes;  the  front 
axle  and  its  steering  connections,  the  driving  axle  and  brakes,  the 
wheels,  the  tires,  and  the  springs  which  form  a  yielding  connection  be- 
tween the  axles  and  the  frame. 

The  power  plant  of  a  gasoline  automobile  is  composed  of  a  num- 
ber of  distinct  devices  of  which  the  engine  proper  is  the  most  impor- 
tant, though  all  of  them  are  necessary  to  insure  practical  operation. 
In  order  to  describe  power  plant  construction  logically,  it  may  be 
divided  into  six  distinct  assemblies,  each  of  which  may  be  resolved 
into  the  various  parts  of  which  they  are  composed.  The  most  im- 
portant assembly  is  the  motor;  then  the  gas-supply  system,  the  igni- 
tion apparatus,  the  devices  used  for  lubrication,  the  system  of  cooling, 
and  the  muffler  assembly. 

The  power  transmission  mechanism  is  the  next  group  of  impor- 


48  The  Modern  Gasoline  Automobile 

tance.  In  this  assembly  one  places  the  clutch,  the  gearset,  the  driving 
means,  and,  in  most  instances,  the  rear  axle  and  traction  members. 

Arrangement  of  Parts  Varies. — In  the  conventional  car  the  motor 
is  usually  placed  at  the  front  end  of  the  frame,  and  the  various  aux- 
iliary devices  are  grouped  around  it.  This  is  the  modern  method 
of  power  plant  placing,  but  even  now  there  are  cars  constructed  in 
which  a  horizontal  engine  is  placed  longitudinally  in  the  frame  par- 
allel with  the  side  members.  This  arrangement  was  formerly  more 
popular  than  it  is  at  present,  because  it  permitted  a  simple  method 
of  power  transmission  by  use  of  single  driving  chain.  In  some  cars 
the  change  speed  gearing  is  placed  in  the  center  of  the  frame,  or 
directly  back  of  the  engine,  as  shown  at  Fig.  1.  In  other  cars  it  may 
be  incorporated  with  the  rear  axle,  as  outlined  in  Fig.  2.  The  final 
drive  to  the  rear  wheels  may  be  by  means  of  shaft  and  universal  joint 
connection,  as  shown  at  Figs.  1  and  2 ;  this  being  the  common  arrange- 
ment on  pleasure  cars;  or  by  means  of  a  combination  of  shaft  and 
chains  used  more  often  on  commercial  vehicles.  This  form  of  drive  is 
shown  at  Figs.  4,  5,  and  6.  The  power  delivered  by  the  motor  crank 
shaft  is  transmitted  to  a  countershaft  which  is  placed  across  the  frame 
by  means  of  a  shaft,  and  from  each  end  of  these  countershafts  the 
energy  is  delivered  to  the  rear  wheels  by  chain  and  sprocket  con- 
nection. 

There  are  many  other  variations  in  arrangement  of  parts  which 
will  be  described  in  proper  sequence.  The  examples  mentioned  are 
given  merely  to  show  that  the  essential  elements  may  be  placed  at 
various  points  in  the  frame  without  impairing  their  utility.  The 
complete  frame  assembly,  including  power  plant  and  exclusive  of  the 
body  or  other  carriage  work,  is  usually  termed  a  "  chassis."  There  is 
no  marked  difference  between  pleasure  or  commercial  vehicle  con- 
struction. The  same  essential  elements  are  incorporated  in  both, 
though  obviously  the  parts  of  a  conveyance  intended  for  industrial 
transportation  are  made  much  heavier  because  of  the  severer  duties 
they  perform  than  those  employed  in  pleasure  cars  which,  neverthe- 
less, may  have  much  greater  power. 

Parts  of  Typical  Automobiles  and  Their  Functions. — A  brief  expla- 
nation of  the  function  of  each  part  of  the  gasoline  car  chassis  de- 
picted at  Fig.  1  will  serve  to  afford  a  better  understanding  of  the 


The  Modern  Gasoline  Automobile  49 

construction  of  an  automobile.  The  purpose  of  the  front  axle  is  not 
unlike  that  of  a  horse-drawn  vehicle,  but  it  is  much  different  in  con- 
struction. The  wheels  are  installed  on  movable  spindles,,  or  steering 
knuckles,  which  are  supported  by  yokes  permitting  one  to  move  the 
wheels  for  steering  rather  than  turning  the  entire  axle  on  a  fifth 
wheel,  or  jack-bolt  arrangement,  as  in  a  horse-drawn  vehicle.  This 
axle  is  attached  to  the  frame  by  spring  members  which  allow  a  certain 
degree  of  movement  without  producing  corresponding  motion  of  the 
frame. 

The  radiator,  which  is  placed  directly  over  the  axle  in  front  of 
the  motor,  is  employed  to  hold  the  water  used  in  keeping  the  engine 
cool  and  is  an  important  part  of  the  heat-radiating  system.  The 
starting  handle  is  a  crank  by  which  the  motor  crank  shaft  is  given 
sufficient  initial  movement  by  the  operator  to  carry  the  engine  parts 
through  one  or  more  portions  of  the  cycle  of  operations,  this  starting 
the  engine.  The  tiebar  joins  the  arms  of  the  steering  spindles  on 
which  the  wheels  revolve,  and  insures  that  these  will  swing  together 
and  in  the  same  direction,  either  to  the  right  or  left.  The  steering 
link,  often  called  the  "  drag  link,"  connects  one  of  the  steering 
knuckles  of  the  front  axle  with  the  steering  gear. 

The  motor  may  be  one  of  the  many  forms  to  be  described  and  one 
of  two  distinct  types.  The  dash  is  a  wooden  or  metal  partition 
placed  back  of  the  power  plant  to  separate  the  engine  from  the  seating 
compartment.  It  is  often  employed  to  support  some  of  the  auxiliary 
apparatus  necessary  to  motor  action  or  some  of  the  control  elements. 
The  clutch  is  a  device  operated  by  a  pedal,  which  permits  the  motor 
power  to  be  coupled  to  the  gearset  and  from  thence  to  the  driving 
wheels,  or  interrupted  at  the  will  of  the  operator.  It  is  used  in  starting 
and  stopping  the  car  and  whenever  the  change  speed  gears  are  shifted. 
The  accelerator  is  a  small  pedal  which  actuates  a  valve  on  the  gas- 
supply  device  to  permit  more  explosive  mixture  being  fed  to  the 
engine  when  it  is  desired  to  increase  the  motor  speed.  Its  function 
is  comparable  to  that  of  the  throttle  of  a  steam  engine.  The  pedals 
are  foot-operated  levers;  one  of  which  releases  the  clutch,  the  other 
applies  the  running  brakes.  The  motor  control  levers  on  the  steering 
column  are  used  in  conjunction  with  the  accelerator  to  vary  the  rota- 
tive speed  of  the  motor  and  thus  regulate  the  energy  produced  in 


50 


The  Modern  Gasoline  Automobile 


proportion  to  the  work  to  be  performed.  The  emergency  brake  lever 
applies  a  powerful  braking  effect  when  it  is  desired  to  stop  the  car 
quickly  and  also  when  one  wishes  to  lock  the  brakes  if  car  movement 
is  arrested  on  a  down  grade.  The  change  speed  lever  operates  the 
sliding  gearing,  which  is  utilized  to  produce  varying  ratios  of  velocity 


Steering  Wheel 

front  Wheel     Water  Outlet       Steering  Pos 
Radiator  \  Exhaust  Pipes 


Emergency  Brake  Leuet 
.Gear  Shift  Lever 


Rear  Wheel 
/ 
Rear  Spring 


Fig.  3. — Side  Elevation  of  Sheffield-Simplex  Six-Cylinder  Chassis;  a  Typical 
Design  of  English  Derivation. 

between  the  engine  shaft  and  ihe  rear  wheel.  The  steering  wheel  actu- 
ates the  mechanism  which  moves  the  wheels  to  the  right  or  left  when 
one  wishes  to  describe  the  circle,  turn  a  corner,  or  otherwise  deviate 
from  a  straight  line. 

The  change  speed  gear  is  one  of  the  most  important  elements  of 
the  power  transmission  system  and  in  connection  with  the  clutch  it  is 
much  used  in  operating  and  controlling  the  vehicle.  The  function  of 
the  frame  has  been  previously  described.  The  exhaust  pipe  is  em- 
ployed to  convey  the  inert  gases  discharged  from  the  motor  cylinders 
to  a  device  known  as  the  muffler  which  is  designed  to  reduce  gas  pres- 
sure by  augmenting  the  volume  and  thus  diminish  the  noise  made  as 
it  issues  to  the  atmosphere.  The  driving  shaft  transmits  power  from 
the  change  speed  gearset  to  the  bevel  gearing  in  the  rear  axle. 

A  universal  joint  is  a  positive  connection  which  permits  a  certain 

degree  of  movement  between  two  shafts  which  must  be  driven  at  the 

same  speed.     One  or  the  other,  or  both,  may  move  in  a  lateral  or  ver- 

-tical  plane  to  a  limited  extent  without  interrupting  the  drive  or  cramp- 


The  Modern  Gasoline  Automobile  51 

ing  the  moving  parts.  The  rear  construction  houses  the  differential 
and  driving  gears,  and  the  shafts  or  axles  which  transmit  the  power 
to  the  traction  wheels.  Brakes  are'  used  to  retard,  or  stop,  the  move- 
ment of  the  wheels,  and  are  operated  by  rods  which  transmit  the 
force  the  operator  applies  at  the  brake  pedal  or  hand  lever  to  the 
brake  band.  Torque  members  are  used  to  maintain  a  definite  relation 
between  the  driving  gears  in  the  axle  and  those  in  gearset,  and  to 
take  the  driving  thrusts  off  the  axle  and  the  strains  imposed  by  brak- 
ing and  driving  from  the  springs.  The  principles  underlying  opera- 
tion of  each  of  the  parts  shown  and  the  number  of  different  forms  in 
which  they  may  exist,  will  be  described  more  extensively  in  the  chap- 
ters dealing  fully  with  the  various  groups. 

Assembling  Typical  Chassis. — The  parts  which  compose  the  mod- 
ern automobile  and  their  relation  to  each  other  can  be  very  easily  as- 
certained and  understood  by  even  those  deficient  in  mechanical  knowl- 
edge, by  consulting  Figs.  8  to  13,  inclusive.  These  show  the  various 
steps  in  assembling  a  typical  American  car,  and  have  been  prepared 
by  the  Locomobile  Company  to  show  the  ease  with  which  their  cars 
may  be  assembled,  or  dismantled,. 

At  Fig.  8,  A  is  shown  the  bare  pressed  steel  frame  which  forms  the 
basis  of  practically  all  motor  cars,  before  any  of  the  other  parts  have 
been  added  to  it.  It  will  be  seen  that  it  consists  of  two  side  members 
of  pressed  steel,  these  usually  being  a  channel  section.  The  two  side 
members  are  joined  by  a  series  of  four  cross  pieces.  The  wide  one  at 
the  front  end  serves  to  support  the  radiator  and  the  starting  crank. 
The  two  which  are  placed  a  little  forward  of  center  in  the  chassis  are 
utilized  to  support  the  change  speed  gear  case.  The  rear  cross  mem- 
ber is  employed  solely  as  a  bracing  piece,  and  is  reinforced  by  two 
triangular  gusset  plates.  All  the  frame  members  are  securely  joined 
together  by  steel  rivets.  It  will  be  noticed  that  the  front  end  of  the 
frame  is  narrower  than  the  rear  portion.  This  is  to  permit  the  front 
wheels  to  assume  a  more  abrupt  angle  than  would  be  the  case  if  the 
frame  bars  were  not  cambered.  This  permits  one  to  maneuver  the 
car  more  easily  in  narrow  streets  because  it  permits  one  to  turn  more 
briskly. 

At  Fig.  8,  B,  several  parts  have  been  added  to  the  frame.  The 
front  springs  have  been  attached  directly  under  the  front  end,  and 


Wheel 


Steering  Wheel 


Traction  Wheel 


Fig.  5.— Plan  View  of  Light  American  Motor  Truck  Chassis. 
52 


53 


54 


The  Modern  Gasoline  Automobile 


the  front  axle  has  been  installed  and  fastened  to  the  springs  by  means 
of  clips.  The  supporting  springs  at  the  back  end  as  well  as  the  front 
and  rear  shackles  or  hangers  have  also  been  installed.  Attention  is 
called  to  the  method  of  supporting  the  rear  ends  of  the  rear  springs 


Spark  Advance  Leuer 
Throttle  Leuer 


Gear  Shift  Leuer 
Emergency  Brake 


Steering  Wheel 


Radiator 


Power  Plant 


Hub 


Tire 


Fig.  7. — Front  View  of  Gasoline  Pleasure  Car  Chassis  with  Section  of  Radiator 
Broken  Away  to  Show  Placing  of  Power  Plant  in  Frame. 

by  a  through  bar  which  passes  through  the  two  side  members,  serving 
very  effectively  as  an  additional  brace. 

The  illustration  at  Fig.  9,  C  depicts  the  chassis  after  the  headlight 
supporting  brackets,  or  lamp  irons,  the  motor  or  complete  power  plant 
and  the  dash  have  been  placed  in  their  proper  positions.  The  appear- 


Radiator  Bar 


Frame 
•  Side  Members 


Steering . 
Knuckl* 


Ctuss  Member 


Qusaet 


Spring    Support 


Fig.  s. — Showing  Typical  Pressed  Steel  Frame  which  Forms  the  Foundation  of 
the  Modern  Gasoline  Automobile  before  Placing  Parts  of  the  Mechanism. 

55 


Lamp   Irons 


FlyuuheeJ 


OL 

Gearbox  -* 

d 

D 

6 

\ 

! 

w 

o\                      / 

: 

i-i 

0 

Fig.  9.— Views  Detailing  Further  Steps  in  Assembling  Typical  Gasoline  Car 

Chassis,  Illustrating  Location  of  Motor  and  Gear  Box. 

56 


Fig.  10.— How  the  Pleasure  Car  Chassis  Looks  with  Rear  Axle  Installed  and 

Gearset  Coupled  to  Engine. 

57 


Rear  Uniugrsal  Joint 


Fig.  11.— After  Driving  Shaft,  Steering  Wheel,  and  Control  Levers  are  Added 

the  Chassis  begins  to  Assume  a  Finished  Appearance. 

58 


Cooling  Fan 


Exhaust  Pipe 


Fig.  12.— Plan  View  of  Chassis  when  Radiator,  Cooling  Fan,  and  Muffler  have 

Been  Put  in  their  Proper  Places. 

59 


Tire 


Step  Hanqers 


Traction  Wheel 


Front  Wheel 


Running  Board 


Rods 


Brake    Drum 


Fig.  13.— The  Finished  Chassis  as  it  Appears  After  the  Front  Wheels,  Tires, 
Traction  Wheels,  Brake  Drums,  Running  Boards  and  Finishing  Touches 
Have  Been  Made. 

60 


The  Modern  Gasoline  Automobile  61 

ance  after  the  change  speed  gear  box  has  been  fastened  to  the  two 
center  cross  members  is  shown  at  D.  It  will  be  noted  that  the  power 
plant  is  attached  directly  to  the  frame  side  members  by  means  of  arms 
or  lugs  extending  from  the  engine  base.  These  are  firmly  bolted  to 
the  frame  sides  and  the  motor  bed  forms  a  very  strong  member  which 
serves  to  keep  the  two  sides  of  the  frame  together. 

The  views  at  Fig.  10  show  further  steps  in  the  process  of  making 
a  motor  car.  At  E,  the  motor  fly  wheel  has  been  joined  to  the  gear 
box  by  means  of  a  clutch  and  driving  coupling.  At  F,  the  rear  axle 
has  been  bolted  to  the  springs  and  the  radius  or  distance  rods  have 
been  installed. 

At  Fig.  11  the  chassis  begins  to  assume  a  more  finished  appear- 
ance. Eeferring  to  G,  it  will  be  seen  that  the  gear  box  has  been  con- 
nected to  the  rear  axle  by  means  of  a  driving  shaft  which  has  a  uni- 
versal joint  at  each  end.  The  torque  rod,  which  is  a  member  designed 
to  resist  braking  and  driving  torque  stresses  and  to  maintain  a  fixed 
distance  between  gear  box  and  rear  axle,  has  been  put  in  place.  At 
H,  the  steering  post,  on  which  are  placed  the  motor  control  levers  and 
steering  wheel,  has  been  fastened  to  the  frame  side  member  and  the 
steering  mechanism  has  been  joined  to  the  front  axle  by  the  drag  link. 
The  gear  shift  and  emergency  brake  levers  have  also  been  placed. 

Inspection  of  Fig.  12  will  show  the  radiator  and  cooling  fan  on 
the  extreme  front  of  the  frame,  almost  directly  over  the  front  axle, 
and  that  the  power  plant  has  been  joined  to  the  radiator  by  a  piece  of 
rubber  hose.  The  exhaust  pipe  and  muffler  have  also  been  fitted. 

The  appearance  of  the  complete  chassis,  ready  to  receive  the  body, 
is  shown  at  Fig.  13.  The  parts  added  are  clearly  indicated.  The 
front  axle  has  been  made  complete  by  the  addition  of  the  wheels  and 
tires.  The  rear  construction  has  also  been  finished  by  supplying  the 
traction  wheels,  tires,  and  brake  drums.  The  brakes  have  been  con- 
nected to  the  operating  pedal  and  lever  by  rods;  and  step  hangers, 
which  support  the  running  boards,  have  been  riveted  to  the  frame 
sides.  The  chassis,  as  shown  at  Fig.  13,  is  made  a  finished  car  by  the 
addition  of  a  suitable  body,  gasoline  tank,  sheet  metal  under-pan  to 
protect  the  mechanism  and  mud  guards  which  extend  from  both  ex- 
tremities of  the  running  board  to  the  front  and  rear,  respectively, 
over  the  wheels  to  protect  the  body  from  mud  thrown  by  the  wheels. 


62  The  Modern  Gasoline  Automobile 

v  Wind  Resistance  and  Body  Design. — The  reader  who  studies  closely 
modern  motor-car  design  will  see  that  the  bodies  which  are  popular 
at  the  present  time  are  of  different  form  than  those  which  were  for- 
merly used.  They  are  lower  and  have  gradual  curved  sides.  The 
object  of  this  new  construction,  or  torpedo  body,  as  it  is  called,  is  to 
reduce  wind  resistance  and  also  lessen  the  dust-raising  proclivities 
of  high  speed  automobiles.  The  effect  of  the  air  disturbed  by  a  rap- 
idly moving  vehicle  may  be  easily  observed  during  the  Fall  when  the 
weather  is  settled  and  the  ground  is  well  covered  with  leaves.  When 
a  car  is  driven  along  the  road  at  moderate  velocities  a  careful  observer 
will  detect  movement  of  leaves  fifteen  or  eighteen  feet  away  from  and 
at  the  side  of  the  car.  This  shows  that  they  have  been  affected  by  the 
large  volume  of  air  set  in  motion  by  the  car  body.  It  is  obvious  t(hat 
dry  dust  would  be  disturbed  in  a  similar  manner,  and  if  special  atten- 
tion was  not  directed  toward  reducing  the  air  movement  any  motor 
car,  even  if  moving  at  moderate  speeds,  would  leave  a  cloud  of  dust 
in  its  wake. 

Dust  disturbance  is  not  the  most  important  factor,  however,  in 
determining  body  form,  but  it  is  the  resistance  of  the  air  that  is  taken 
into  consideration  because  .of  power  absorbed.  The  object  in  design- 
ing should  be  to  reduce  end  on  resistance  area  to  as  low  a  point  as 
possible,  because  the  less  area  one  has  to  push  through  the  air,  the  less 
power  it  will  take  to  overcome  air  resistance  and  more  energy  can 
be  expended  in  driving  the  car. 

At  Fig.  14,  the  front  view  of  a  typical  motor  car  is  shown  with 
dimensions  which  indicate  the  approximate  size.  To  ascertain  the 
total  area,  one  or  two  points  require  consideration.  The  radiator, 
which  is  the  largest  member  setting  at  a  vertical  plane,  cannot  be  con- 
sidered as  offering  an  area  that  its  overall  dimensions  would  indicate. 
A  large  volume  of  air  passes  through  it,  but  by  no  means  all  the  air 
that  passes  between  the  tubes  and  the  radiator  discharges  without 
resistance.  Some  of  it  flows  easily  around  the  power  plant,  and  some 
streams  out  under  the  floor  boards,  especially  if  these  are  inclined. 
The  greater  part  of  the  air  which  passes  through  the  radiator  must 
be  deflected  by  the  vertical  dashboard  which  separates  the  motor 
compartment  from  the  bod)-,  and  the  reaction  due  to  this  cause  is  com- 
parable to  the  resistance  which  would  obtain  if  the.  radiator  was  prac- 


The  Modern  Gasoline  Automobile 


63 


tically  solid.  It  is  estimated  that  the  resistance  of  the  average  radi- 
ator may  be  safely  considered  at  about  half  that  of  a  solid  plane 
surface  of  equal  dimensions. 

The  resistance  of  the  curved  mud  guards  can  be  assumed  to  be 
that  of  their  projected  area,  because  the  usual  angle  of  inclination  is 


Fig.  14.— Front  View  of  Typical  Gasoline  Car  of  Modern  Design,  Showing  Parts 
which  Tend  to  Impede  Speed  of  Car  by  Producing  Air  Resistance. 

such  that  the  total  pressure  upon  their  underside  may  be  taken  as 
the  same  that  would  exist  if  they  were  not  inclined  appreciably.  In 
addition,  one  may  figure  the  area  of  a  wind  shield  and  top,  and  when 
all  these  factors  are  considered,  the  approximate  end  on  resistance 
of  the  average  touring  car  will  vary  from  twenty  to  twenty-five  feet. 
The  amount  of  power  which  will  be  needed  to  overcome  this  re- 
sistance can  be  easily  computed  on  a  basis  of  speed  of  thirty  miles  per 


64 


The  Modern  Gasoline  Automobile 


hour.  The  power  required  to  overcome  air  resistance  varies  as  the 
cube  of  the  speed,  and  therefore  if  the  velocity  is  doubled,  making  it 
sixty  miles  per  hour,  the  power  absorbed  at  half  that  speed  will  be 
increased  in  value  eight  times.  The  following  table  indicates  the 
power  absorbed  by  air  resistance  at  various  speeds,  assuming  a  total 
end  on  area  of  twenty-three  square  feet: 


M.  P.  H. 

H.  P.  ABSORBED 

M.  P.  H. 

H.  P.  ABSORBED 

10 

.174 

50 

21.75 

20 

1.392 

60 

40.00 

30          * 

/.&*?§-£.  QQfr- 

70 

59.68 

40 

11.136 

80 

89.08 

If  one  consults  the  table  presented  above  it  will  be  evident  that 
cars  running  at  speeds  of  thirty  miles  per  hour,  or  less,  are  not  seri- 
ously affected  by  air  resistance,  but  just  as  soon  as  the  speed  augments 
it  will  be  apparent  that  it  is  very  desirable  to  reduce  the  frontal  area 
directly  exposed  as  low  as  possible 

At  Figs.  15  and  16,  diagrams  are  presented  to  indicate  the  prob- 
able direction  of  the  air  currents  around  an  ordinary  type  fore  door 


Fig.  16. — Side  View  of  Typical  Gasoline  Car,  Demonstrating  Influence  of  Body 

Form  on  Air  Flow. 

body  with  square  dashboard  and  wind  shield  raised  to  a  vertical 
position.  These  may  be  compared  to  advantage  with  the  views  shown 
at  Figs.  17  and  18,  which  represent  the  same  phenomena,  except  that 


Tlie  Modern  Gasoline  Automobile 


65 


the  car  is  provided  with  a  better  designed  body  and  a  tapered  hood, 
and  that  the  wind  shield  is  tilted  instead  of  being  set  vertical.  The 
diagrams  are  very  instructive,  and  it  should  be  noted  in  this  connec- 
tion that  eddy  currents  would  be  largely  increased  if  no  side  doors 
were  fitted  to  the  front  seats.  With  a  body  of  the  stream  line  form 
the  air  currents  are  not  deflected  abruptly  but  follow  the  outline 
of  the  curved  body  and  do  not  tend  to  raise  as  much  dust  or  offer 
the  same  resistance  as  that  present  at  Figs.  17  and  18. 


Fig.  16.— Plan  View  Showing  Path  of  Air  Currents  Around  Body  of  Gasoline 
Car  when  No  Attempt  Has  Been  Made  to  Secure  Lessened  Air  Resistance. 

In  order  to  show  how  much  resistance  may  be  obviated  by  the  use 
of  a  stream  line  body,  it  is  well  to  consider  a  typical  example.  Con- 
sider a  car  which  is  equipped  with  a  seventy-horse-power  engine  and 
which  track  tests  have  demonstrated  capable  of  ninety  miles  per  hour. 
From  the  horse  power  available  for  overcoming  the  wind  resistance 
we  can  deduct  a  certain  amount  which  will  be  absorbed  by  friction 
of  the  transmission  mechanism  and  loss  between  tires  and  track.  The 
loss  due  to  the  driving  gearing  can  be  assumed  to  be  twenty-five  per 
cent,  and  that  due  to  loss  between  tires  and  roadway  is  estimated  at 
ten  per  cent.  This  will  make  a  total  loss  of  thirty-five  per  cent,  which 
result  will  be  sufficiently  near  the  truth  for  purpose  of  approximation. 
The  available  horse  power  is  therefore  sixty-five  per  cent  of  seventy 
horse  power,  or  in  round  numbers  forty-five  horse  power.  It  would 


66 


The  Modern  Gasoline  Automobile 


seem  that  the  less  area  one  had  the  greater  ^speeds  possible  with  the 
horse  power  available.  In  order  to  attain  a  speed  of  ninety  miles  per 
hour  one  could  only  have  an  exposed  area  of  about  eight  square  feet. 


Fig.  17. — Depicting  Flow  of  Air  Currents  Around  Torpedo  Body;  Designed  to 
Reduce  Friction  of  Atmosphere  at  High  Speeds. 

This  would  call  for  a  stream  line  form  racing  body  similar  in 
design  to  that  shown  at  Fig.  19.    It  will  be  seen  that  the  air  currents 


Fig.  18. — Plan  View  of  Vehicle  Body  Shown  in  Preceding  Illustration,  which 
Clearly  Indicates  Influence  of  Symmetrical  Body  Form  in  Promoting  Less- 
ened Air  Resistance. 


The  Modern  Gasoline  Automobile  67 

follow  the  body  contour  very  closely.  As  the  body  is  flush  sided  with 
no  openings  or  projections  to  disturb  air  flow,  it  will  be  evident  that 
the  minimum  of  exposed  area  will  permit  a  maximum  speed.  Ob- 


Fig.  19. — Outline  of  Exaggerated  Torpedo  Body  Type,  Seldom  Seen  Except  in 

Racing  Cars. 

viously,  a  practical  touring  car  cannot  be  designed  on  exactly  the 
same  lines  as  a  racing  vehicle,  as  too  milch  of  the  operator's  comfort 
would  have  to  be  sacrificed  to  attain  this  end.  A  practical  form  of 
stream  line  body  fitted  to  a  roadster  chassis  is  shown  at  Fig.  20,  while 
a  fore-door,  five-passenger  touring  car  is  depicted  in  outline  at  Fig.  21. 


Fig.  20. — Typical  Modern  Roadster  Chassis  Fitted  with  Fore-Door  Body,  Show- 
ing Application  of  Steam  Line  Body  Form  in  Practice. 

Factors  which  Determine  Power  Required. — When  a  motor  car  is 
in  operation  there  are  various  forces  tending  to  resist  its  motion,    On 


68 


The  Modern  Gasoline  Automobile 


a  level  road  these  are  the  rolling  resistance  at  the  point  of  contact  of 
the  traction  wheels  and  the  roadway;  friction  in  the  power  trans- 
mission mechanism  and  atmospheric  resistance.  If  the  vehicle 


is 


Fig.  21. — Application  of  Fore-Door,  Five-Passenger  Touring  Body  to  Gasoline 

Car  Chassis. 

moving  on  a  gradient  there  is  still  another  factor  to  be  considered, 
and  this  is  the  amount  of  power  needed  to  raise  the  weight  of  the 
car  against  the  force  of  gravity.  Obviously  when  the  car  is  descend- 
ing a  hill  the  force  of  gravity  assists  the  power  plant  instead  of  work- 
ing against  it. 


Fig.  22.— The  Coupe",  a  Popular  Form  of  Closed  Body  Favored  by  Professional 

Men. 


The  Modern  Gasoline  Automobile 


69 


The  resistance  of  the  road  depends  very  largely  upon  the  nature 
of  the  surface,  and  it  is  also  dependent  upon  the  size  of  the  wheels 
and  type  of  tire  with  which  they  are  fitted.  The  second  item,  that 
of  friction  of  rear  axle,  drive  shaft,  bearings  and  change  speed  gears, 
is  comparatively  low,  and  it  is  generally  included  with  that  of  road 
resistance.  It  will  be  evident  that  other  factors  must  also  be  con- 
sidered in  determining  power  required  to  propel  a  vehicle.  One  must 
figure  on  the  total  weight  of  the  car,  the  capacity  of  the  body,  and 


Fig.  23.— The  Rockwell  Taxicab,  or  Public  Service  Vehicle,  with  Convertible 
Type  Body,  which  May  be  Used  as  Shown  and  which  Becomes  a  Closed 
Car  when  the  Top  is  Raised. 

the  maximum  speed  it  is  desired  to  attain.  All  of  these  factors  are 
considered  by  the  designer,  but  the  usual  practice  is  to  assume  an 
average  set  of  conditions  and  to  provide  a  motor  of  more  power  than 
is  absolutely  needed  to  secure  a  margin  of  safety  over  the  require- 
ments. 

-  Classification  of  Motor-Car  Types. — In  considering  the  automobile 
one  may  divide  it  into  a  number  of  distinct  types.     These  in  turn, 
belong  to  one  of  two  main  classifications.     When  cars  are  used  for 
industrial  purposes,  such  as  hauling  freight  and  delivering  merchan- 


70 


The  Modern  Gasoline  Automobile 


dise,  they  are  commonly  termed  commercial  cars,  or  motor  trucks.  If 
the  automobile  is  used  solely  for  transporting  people  such  as  in  tour- 
ing, or  even  for  business  purposes,  it  is  termed  a  pleasure  car,  though 
the  line  of  demarcation  between  one  class  and  the  other  is  sometimes 
difficult  to  define. 

There  is  no  great  difference  in  construction  of  the  essential  ele- 
ments of  either  form.  One  chassis  may  be  fitted  with  many  different 
body  types,  some  of  which  may  be  specially  designed  for  commercial  use 
while  others  may  be  intended  solely  for  personal  transportation.  The 


Fig.  24. — One-and-one-half  Ton  Capacity  White  Truck ;  a  Conventional  Example 
of  American  Commercial  Car  Having  Power  Plant  Located  Under  the  Hood, 
as  in  Pleasure  Car  Practice. 

chassis  of  the  vehicle  contrived  solely  for  use  in  conveying  merchan- 
dise is  built  heavier  and  stronger  than  one  built  only  to  carry  pas- 
sengers, and  there  are  certain  modifications  in  detail.  The  princi- 
ples of  operation  6f  the  essential  elements  such  as  power  plant,  con- 
trol systems,  driving  means,  axle  construction,  etc.,  are  the  same,  and 
no  attempt  will  be  made  to  differentiate  between  the  types  except  in 
cases  where  the  construction  differs  radically  from  accepted  or  general 
practice. 

As  an  example  of  the  difficulty  in  isolating  the  types  a  form 
which  may  belong  to  either  classification  is  shown  at  Fig.  23.  If 
used  as  a  town  car  for  social  calls,  shopping,  etc.,  it  might  be  classed 


The  Modern  Gasoline  Automobile 


71 


properly  as  a  pleasure  car,  whereas  if  employed  as  a  public-service 
vehicle,  or  taxicab  for  hire,  it  belongs  to  the  other  classification.    The 


Fig.  25. — Front  and  Rear  Elevation  of  Special  Sampson  Truck,  Designed  for 
United  States  Army  Service. 


Fig.  26. — Side  View  of  Sampson  Army  Type  Transport  Wagon. 


72 


The  Modern  Gasoline  Automobile 


truck  shown  at  Fig.  24  is  a  good  example  of  the  way  pleasure  car  prac- 
tice may  be  altered  for  commercial  purposes.    The  parts  are  strength- 


Fig.  27. — Showing  Typical  American  Motor  Truck  Design  in  which  Power  Plant 
is  Placed  Under  Operator's  Feet,  thus  Providing  More  Carrying  Space  for 
Body  without  Lengthening  Wheel  Base. 

ened,  but  the  general  design  as  regards  disposition  of  the  parts  of  the 
mechanism  is  very  similar  to  that  which  obtains  in  representative 


Fig.  28.— Motor  Truck  Chassis  Fitted  with  Special  Body  for  Fire  Department 
Service;  a  New  Field  to  which  the  Gasoline  Motor  is  Particularly  Well 
Adapted. 


Fig.  29.— Showing  Different  Body  Forms  Fitted  to  Same  Chassis  Type. 

73 


74 


The  Modern  Gasoline  Automobile 


Motor  in  Front 
under  Hood 


Radiator 


Dashboard 


Brake  Rods 


Dual  Tires' 


Motor  Control 
Steering  Wheel 

Operating  Leuer. 


Clutch  and 
7Brake  Pedals 


Change  Speed  Gearing 


Universal  Joint 


Brake  Rods 
Driving  Shaft 

Frame  Side  Member 

Rear  Axle  and 

Differential 

Qeo.rca.se 


Rear  Spring? 


Fig.  30. — Light  Motor  Truck  Chassis  which  Follows  Typical  Pleasure  Vehicle 
Design  Except  in  Size  of  Parts.  The  Frame  and  Running  Gear  are  Heavier 
and  Stronger  to  Compensate  for  the  Greater  Load-Carrying  Capacity. 


Tlie  Modern  Gasoline  Automobile  75 

pleasure  cars.  Figs.  25  to  28  inclusive,  depict  vehicles  which  have  been 
designed  for  special  industrial  requirements  and  can  be  placed  in  the 
commercial  car  class  without  hesitation,  because  the  bodies  fitted  and 
the  general  design  or  arrangement  of  components  does  not  permit 
their  use  for  any  purpose  other  than  that  for  which  they  were  con- 
trived. All  the  body  forms  shown  at  Fig.  29  are  applied  to  the  same 
type  chassis,  and  it  is  very  common  practice  to  design  the  running 
gear  and  frame  so  it  may  be  adapted  to  a  wide  range  of  work  without 
changing  location  of  the  mechanical  parts. 


CHAPTEE   II 

How  Power  is  Generated — Two-  and  Four-Cycle  Engine  Action — Features  of 
Sleeve  Valve  Motor — Principal  Engine  Types  Described — One-  and  Two- 
Cylinder  Engines — Advantages  of  Four-  and  Six-Cylinder  Forms — Power 
Plant  Location. 

IT  has  been  previously  stated  that  the  gasoline  automobile  may 
be  divided  into  groups  and  that  these  various  assemblies  all  have 
their  important  work  to  do  and  that  each  depend,  to  some  extent, 
upon  the  correct  action  of  the  others  to  insure  a  smooth  working 
motor  car.  The  most  important,  and  the  least  understood,  element 
is  the  power  plant,  and  it  is  important  that  the  prospective  motorist 
familiarizes  himself  with  the  principles  of  gasoline  engine  operation 
in  order  to  easily  locate  troubles  and  derangements  which  interfere 
with  correct  action.  If  the  operator  is  familiar  with  the  basic  prin- 
ciples of  internal  combustion  engine  action  it  will  not  be  difficult  to 
apply  this  knowledge  to  all  forms  of  gasoline  motors  used  as  automo- 
bile power  plants. 

Forms  of  Engines  Commonly  Used. — If  one  raises  the  hood  at  the 
front  of  a  motor  car,  one  will  find  a  complete  engine  assembly  very 
much  the  same  as  that  depicted  at  Fig.  31,  which  outlines  a  con- 
ventional engine  with  the  various  auxiliary  parts  lettered  so  that  one 
can  obtain  an  idea  of  their  location  relative  to  each  other. 

Of  the  external  parts  shown  the  carburetor  is  employed  to  mix  the 
gasoline  used  as  fuel  with  a  certain  amount  of  air  in  order  to  form 
a  gas  that  can  be  ignited  in  the  engine  cylinders.  This  explosive 
mixture  is  supplied  to  the  cylinders  by  a  conductor  known  as  the 
inlet  pipe.  The  spark  plugs  and  magneto  form  part  of  the  ignition 
outfit.  The  engine  shown  is  a  four-cylinder  form  and  operates  on 
fhe  four-cycle  principle.  Various  forms  of  engines  have  been  applied 
to  automobile  propulsion,  and  of  the  large  number  of  different  types 
the  majority  operate  on  the  four-stroke  principle,  though  the  two- 
stroke  types  are  simpler.  In  the  latter  there  is  an  explosion  in  each 

76 


The  Modern  Gasoline  Automobile 


77 


cylinder  every  turn  of  the  crank  shaft,  while  the  other  method  pro- 
vides but  one  power  impulse  per  cylinder  every  two  turns  of  the  re- 
volving elements.  Though  the  four-stroke  motor  is  more  complicated 
in  construction  than  the  other  it  is  the  easiest  to  understand.  All  in- 
ternal combustion  motors,  usually  termed  "  gasoline  engines  "  because 
of  the  use  of  this  liquid  fuel,  are  forms  of  heat  motors  owing  to  the 


Oil  Tank 
Spark  Plugs 
Compression  Cocks 

Cylinder- 


Inlet  Pip 


Timer 


Water  Outlet 
Spark  Advance  Hods 


Value  Springs 
Oil  Pipe  to  Bearing 


Lower  Half  of  Crankcase 


Upper  Crankcase 


Fig.  31.— Typical  Motor-Car  Power  Plant,  Showing  External  Appearance  and 
Location  of  Important  Auxiliary  Mechanisms. 

energy  being  produced  by  the  rapid  burning,  or  combustion,  of  a  gas 
which  expands  after  it  is  exploded  and  produces  pressure  that  is 
transformed  into  mechanical  power  by  simple  mechanism.  In  defin- 
ing the  principles  of  four-cycle  motor  action,  one  can  explain  the 
matter  very  clearly  by  comparing  the  effect  produced  by  exploding 
gasoline  gas  to  that  which  obtains  when  one  explodes  gunpowder 
in  a  gun. 


78  The  Modern  Gasoline  Automobile 

How  the  Gasoline  Engine  Works. — At  Fig.  32,  A,  the  upper  view 
shows  a  section  through  a  simple  one-cylinder  gasoline  engine,  while 
the  lower  one  illustrates  an  old  pattern  muzzle  loading  cannon.  Con- 
sidering first  the  phenomena  which  obtains  when  gunpowder  is  burned, 
one  can  obtain  some  idea  of  how  exploded  gasoline  vapor  may  be 
transformed  into  power.  In  fact,  the  preliminary  operations  which 
have  been  necessary  before  the  gun  was  fired,  are  very  similar  to 
those  which  preceded  an  explosion  in  the  cylinder  of  the  gasoline 
engine  of  the  four-cycle  type.  Following  first  the  cycle  of  operations 
necessary  to  fire  the  cannon,  graphically  shown  at  the  lower  portion 
of  Fig.  32,  it  will  be  seen  that  a  certain  sequence  is  necessary.  At 
A  we  have  the  loading,  or  charging  of  the  mortar.  The  powder 
which  is  carried  in  bags  for  convenience  is  introduced  in  the  muzzle 
and  pushed  back  into  the  breech  with  the  ramrod.  After  the  powder 
has  been  compressed  the  ball  is  placed  and  tightly  rammed  in  place 
on  top  of  the  powder  in  the  explosion  chamber,  as  shown  at  B.  After 
the  powder  is  properly  compacted  it  is  exploded  by  means  of  a  lighted 
fuse,  or  percussion  cap,  and  the  cannon  ball  is  forced  out  through 
the  open  end  because  of  the  pressure  of  gas  on  its  underside,  this 
having  been  produced  by  the  rapid  burning  of  the  powder. 

The  next  operation  is  clearing  the  mortar  of  the  burned  gases 
in  order  to  introduce  a  fresh  charge  of  powder  and  shot.  The  clear- 
ing is  automatically  performed,  as  shown  at  D.  As  soon  as  the  ball 
leaves  the  mouth  of  the  mortar  the  gas  which  is  still  under  high  pres- 
sure escapes  to  the  atmosphere.  After  the  barrel  is  swabbed  out,  one 
can  introduce  another  charge  and  fire  the  cannon  again.  The  power 
to  propel  the  shot  through  the  air  has  been  obtained  by  burning  a 
substance  which  before  ignition  had  no  power  to  produce  motion  of 
the  ball.  If  an  equal  charge  of  gunpowder  had  been  placed  in  the 
open  air  and  the  shot  placed  upon  it,  one  would  find  that  if  the  com- 
bustible material  were  ignited,  there  would  be  very  little  energy 
produced.  There  would  be  a  flash  of  flame,  but  it  is  doubtful  that 
this  would  have  sufficient  energy  to  cause  the  cannon  ball  to  leave 
its  position.  Powder  compacted  in  the  cannon  barrel  produced  use- 
ful energy  because  pressure  was  confined  in  a  chamber  having  rigid 
walls  at  all  sides,  except  one,  this  being  the  side  of  the  cannon  ball 
nearest  the  explosive.  The  metal  surrounding  the  explosion  chamber 


The  Modern  Gasoline  Automobile  79 

had  sufficient  strength  to  resist  the  high  gas  pressure,  but  the  ball 
which  was  movable  was  driven  out  because  its  weight  was  not  suf- 
ficient to  resist  the  force  applied  to  it  by  the  exploded  powder. 

It  is  evident  that  burning  powder  in  the  air  will  produce  a  certain 
amount  of  energy,  but  as  the  explosion  takes  place  in  the  open  there 
will  be  nothing  to  restrain  the  pressure,  and  just  as  soon  as  the  powder 
is  lighted  any  energy  evolved  is  dissipated  into  the  atmosphere  instead 
of  the  force  being  directed  against  yielding  members.  The  ball  is 
forced  out  of  the  gun  barrel,  not  only  by  the  gas  .pressure  which  re- 
sults as  soon  as  the  powder  is  exploded,  but  also  by  the  expansion  of 
the  gases  generated  by  combustion  which  tends  to  accelerate  its  motion 
toward  the  end  of  the  barrel.  As  the  shot  moves  toward  the  end  and 
the  gas  occupies  more  space  its  pressure  becomes  less,  and  when  the 
ball  leaves  the  mouth  of  the  motor  there  is  very  little  power  remain- 
ing in  the  moving  gas.  There  is  sufficient  pressure,  however,  so  that 
the  gas  rushes  out  of  the  interior  and  the  barrel  is  thus  cleared  of 
inert  products  which  have  no  useful  force. 

The  action  of  a  modern  repeating  rifle  is  somewhat  different  than 
that  of  a  muzzle  loader,  because  the  powder  is  already  compressed  in 
metal  shells  which  are  introduced  at  the  breech  of  the  gun  instead  of 
at  the  muzzle.  The  number  of  shells  are  carried  in  a  magazine,  and 
after  one  of  these  explodes  the  recoil  due  to  the  explosion  of  the  gas 
supplies  another  charged  shell  to  the  breech  and  the  operation  of  firing 
the  gun  may  be  repeated  as  long  as  the  supply  of  ammunition  in  the 
magazine  lasts. 

The  modern  gasoline  engine  follows  the  action  of  both  the  old 
type  muzzle  loader  and  the  more  modern  form  in  which  the  shell  is 
introduced  at  the  breech.  Referring  again  to  sketches  at  top  of  Fig. 
32,  we  can  compare  the  action  of  a  simple  four-stroke  engine  with 
that  of  a  cannon  which  is  illustrated  below  them.  The  principal 
elements  of  a  gas  engine  are  not  difficult  to  understand  and  their 
functions  are  easily  defined.  In  place  of  the  barrel  of  the  gun  one 
has  a  smoothly  machined  cylinder  in  which  a  small  cylindrical  or 
barrel-shaped  element  fitting  the  bore  closely  may  be  likened  to  a 
bullet  or  cannon  ball.  It  differs  in  this  important  respect,  however, 
as  while  the  shot  is  discharged  from  the  mouth  of  the  cannon  the 
piston  member  sliding  inside  of  the  main  cylinder  cannot  leave  it, 


80  The  Modern  Gasoline  Automobile 

as  its  movements  back  and  forth  from  the  open  to  the  closed  end  and 
back  again  are  limited  by  simple  mechanical  connection  or  linkage 
which  comprises  crank  and  connection  rod.  It  is  by  this  means  that 
the  reciprocating  movement  of  the  piston  is  transformed  into  a  rotary 
motion  of  the  crank  shaft. 

The  fly  wheel  is  a  heavy  member  attached  to  the  crank  shaft 
which  has  energy  stored  in  its  rim  as  the  member  revolves,  and  the 
momentum  of  this  revolving  mass  tends  to  equalize  the  intermittent 
pushes  on  the  piston  head  produced  by  the  explosion  of  the  gas  in  the 
cylinder.  If  some  explosive  is  placed  in  the  chamber  formed  by  the 
piston  and  closed  end  of  the  cylinder  and  exploded,  the  piston  would 
be  the  only  part  that  would  yield  to  the  pressure  which  would  pro- 
duce a  downward  movement.  As  this  is  forced  down  the  crank  shaft 
is  turned  by  the  connecting  rod,  and  as  this  part  is  hinged  at  both 
ends  it  is  free  to  oscillate  as  the  crank  turns,  and  thus  the  piston  may 
slide  back  and  forth  while  the  crank  shaft  is  rotating  or  describing 
a  curvilinear  path. 

In  addition  to  the  simple  elements  described  it  is  evident  that  a 
gasoline  engine  must  have  other  parts.  The  most  important  of  these 
are  the  valves,  of  which  there  are  two  to  each  cylinder.  One  closes 
the  passage  connecting  to  the  gas  supply  and  opens  during  one  stroke 
of  the  piston  in  order  to  let  the  explosive  gas  into  the  combustion 
chamber.  The  other  member,  or  exhaust  valve,  serves  as  a  cover  for 
the  opening  through  which  the  burned  gases  can  leave  the  cylinder 
after  their  work  is  done.  The  spark  plug  is  a  simple  device  which 
may  be  compared  to  the  fuse  or  percussion  cap  of  the  cannon.  It 
permits  one  to  produce  an  electric  spark  in  the  cylinder  when  the 
piston  is  at  the  best  point  to  utilize  the  pressure  which  obtains  when 
the  compressed  gas  is  fired.  The  valves  are  open  one  at  a  time,  the 
inlet  valve  being  lifted  from  its  seat  while  the  cylinder  is  filling  and 
the  exhaust  valve  is  opened  when  the  cylinder  is  being  cleared.  They 
are  normally  kept  seated  by  means  of  compression  springs.  In  the 
simple  motor  shown  at  Fig.  32,  the  exhaust  valve  is  operated  by  means 
of  a  pivoted  bell  crank  rocked  by  a  cam  which  turns  at  half  the  speed 
of  the  crank  shaft.  The  inlet  valve  operates  automatically,  as  will 
be  explained  in  proper  sequence. 

Considering  the  view  shown  at  Fig.   32,  A,  the  first  necessary 


The  Modern  Gasoline  Automobile  81 

operation  is  charging  the  cylinder  with  explosive  material.  The 
piston  is  at  the  top  of  its  stroke  and  it  moves  toward  the  open  end 
of  the  cylinder.  The  engine  works  as  a  pump,  and  the  piston  draws 
in  a  charge  of  combustible  gas  through  the  open  intake  valve,  which 
is  in  connection  with  the  vaporizer  which  furnishes  the  gas.  An  auto- 
matic valve  opens  because  of  a  light  vacuum  or  suction  existing 
when  the  piston  has  traveled  down  a  certain  portion  of  its  stroke,  and 
then  the  outside  air  pressure  is  greater  than  that  in  the  cylinder.  The 
external  air  pressure  is  greater  than  the  tension  of  the  spring  which 
tends  to  keep  the  valve  closed  and  the  member  is  therefore  drawn 
from  its  seat  by  the  piston.  At  the  end  of  the  intake  stroke,  which 
is  shown  at  Fig.  32,  A,  and  after  the  cylinder  has  filled  with  gas  the 
pressure  inside  and  outside  is  the  same  and  the  valve  spring  closes 
the  intake  valve.  As  the  exhaust  valve  spring  is  very  strong  this 
member  has  not  been  lifted  from  its  seat  by  the  difference  in  pres- 
sure. The  exhaust  valve  is  opened  by  mechanical  means  solely  and 
only  when  operated  by  the  cam  and  push-rod  mechanism. 

The  condition  in  the  cylinder  and  the  gas  engine  after  the  piston 
has  reached  the  bottom  of  its  stroke  is  -.very  much  the  same  as  that 
which  obtains  in  a  gun  of  the  muzzle-loading  type  after  the  explo- 
sive charge  has  been  introduced.  We  have  learned  that,  to  obtain 
power  from  gunpowder,  it  was  necessary  to  compact  it  firmly  in 
the  combustion  chamber  of  the  gun.  The  gasoline  gas  which  has 
been  taken  into  the  engine  cylinder  must  also  be  compressed  before 
it  is  ignited,  in  order  to  obtain  power.  It  is  compacted  into  one- 
third  or  one-quarter  of  its  former  volume,  and  whereas  its  pressure 
is  about  fifteen  pounds  per  square  inch  before  it  is  compacted  at  the 
end  of  the  compression  stroke  of  the  piston  the  pressure  will  be  in- 
creased to  forty-five,  sixty,  and  even  seventy-five  pounds  per  square 
inch.  At  the  end  of  this  compression  stroke,  which  is  shown  at  B,  the 
conditions  in  the  engine  cylinder  are  the  same  as  those  which  prevail 
in  the  barrel  of  the  cannon  after  the  powder  has  been  tightly  rammed 
in  the  closed  end  of  the  gun  barrel  and  the  ball  is  forced  in  on  top 
of  it.  At  C  we  have  seen  that  the  powder  was  fired  by  means  of  a 
fuse.  The  compressed  gas  in  the  engine  cylinder  is  exploded  elec- 
trically by  a  spark  occurring  between  the  points  of  the  spark  plug. 
The  explosion  in  the  cannon  drives  out  the  ball,  while  that  in  the 


82  The  Modern  Gasoline  Automobile 

engine  cylinder  forces  the  piston  out  and  causes  the  crank  shaft  and 
fly  wheel  attached  to  it,  to  revolve. 

In  order  to  obtain  a  perfectly  tight  combustion  chamber,  both 
intake  and  exhaust  valves  are  closed  before  the  gas  is  ignited,  because 
all  of  the  pressure  produced  by  the  exploding  gas  is  to  be  directed 
against  the  top  of  the  movable  piston.  When  the  piston  reaches  the 
bottom  of  its  power  stroke,  as  indicated  at  D,  the  exhaust  valve  is 
lifted  by  means  of  the  bell  crank  which  is  rocked  because  of  the  point 
or  lift  on  the  cam.  The  cam  shaft  is  driven  by  positive  gearing  and 
revolves  at  half  the  engine  speed.  The  exhaust  valve  remains  open 
during  the  whole  of  the  return  stroke  of  the  piston,  and  as  this  mem- 
ber moves  toward  the  closed  end  of  the  cylinder  it  forces  out  burned 
gases  ahead  of  it,  through  the  passage  controlled  by  the  exhaust  valve. 
The  cam  shaft  is  revolved  at  half  the  engine  speed  because  the  ex- 
haust valve  is  raised  from  its  seat  during  only  one  stroke  out  of 
four,  or  only  once  every  two  revolutions.  Obviously,  if  the  cam  was 
turned  at  the  same  speed  as  the  crank  shaft  it  would  remain  open 
once  every  revolution,  whereas  the  burned  gases  are  expelled  only  once 
in  two  turns  of  the  crank  shaft. 

It  will  be  evident  that  three  "strokes  of  the  piston  are  necessary  to 
secure  one  useful  explosion  just  as  practically  three  operations  are 
needed  to  fire  the  cannon.  The  first  downward  movement  of  the 
piston  fills  the  cylinder  with  gas  and  is  known  as  the  "  intake  stroke." 
This  is  accomplished  during  the  first  half  revolution  of  the  crank 
shaft.  The  return  movement  of  the  piston  is  accomplished  during 
the  second  half  of  the  first  revolution  and  compacts  the  gas  previously 
inspired.  This  is  called  the  "  compression  stroke/'  The  expansive 
force  back  of  the  piston  producecl  by  the  explosion  forces  the  piston 
down  again,  this  turning  the  crank  shaft  through  the  first  half  of 
the  second  revolution  which  is  known  as  the  "  power  stroke."  The 
last  half  of  the  second  revolution  produces  a  return  movement  of  the 
piston  toward  the  closed  end,  and  as  the  burned  gases  are  expelled 
and  the  cylinder  is  cleared  to  receive  the  fresh  charge,  this  movement 
of  the  piston  is  known  as  the  "  exhaust  stroke."  The  cycle  of  opera- 
tions described  is  continued  and  repeats  as  long  as  the  cylinder  is 
supplied  with  fuel,  the  spark  takes  place  to  fire  the  gas  and  the 
engine  prevented  from  overheating  by  means  of  lubrication  between 


tl 

|3 


P 


5 


s. 


>  § 


83 


84  The  Modern  Gasoline  Automobile 

all  moving  parts  and  cooling  those  portions  liable  to  become  exces- 
sively hot  by  suitable  extraneous  means. 

%  Typical  Single-Cylinder  Engines  Described. — The  gasoline  engine 
may  have  any  number  of  cylinders,  though  the  conventional  types 
used  in  automobile  propulsion  seldom  use  any  but  an  even  number 
and  rarely  more  than  six.  At  one  time  single-cylinder  motors  were 
very  popular.  These  were  used  in  both  the  horizontal  and  vertical 
types.  A  typical  form  of  horizontal  motor  is  shown  at  Fig.  33. 
Power  plants  of  this  type  were,  for  the  most  part,  of  low  power  and 
were  patterned  largely  after  stationary  gasoline  engine  practice  as 
far  as  proportion  of  parts  was  concerned.  They  were  heavy  and  oper- 
ated at  low  speed.  Such  engines  are  seldom  employed  at  the  present 
time,  except  in  cars  of  ancient  construction,  many  of  which  are  still 
in  use.  Though  this  type  of  motor  was  comparatively  slow  acting 
and  considerable  vibration  existed  while  it  was  in  operation,  they 
were  strongly  constructed  and  capable  of  giving  very  satisfactory 
service.  Engines  of  this  type  are  usually  installed  under  the  body, 
the  engine  cylinder  being  parallel  with  the  frame  side  member  while 
the  crank  shaft  was  at  right  angles  to  it.  This  permitted  a  very 
simple  and  efficient  method  of  power  transmission  as  the  change 
speed  gearing  which  was  usually  carried  on  the  crank  shaft  extension 
could  be  easily  coupled  to  the  rear  axle  by  means  of  a  single  chain 
and  a  pair  of  sprockets. 

Owing  to  the  vibration  which  obtains  from  the  heavy  explosion 
in  the  large  single-cylinder  engine  other  forms  were  evolved  in  which 
the  cylinder  was  smaller  and  power  obtained  by  running  the  engine 
faster.  The  single-cylinder  motor  of  the  vertical  type  is  shown  at 
Fig.  34.  The  pattern  shown  at  Fig.  33  is  distinctively  of  American 
derivation  and  was  designed  to  avoid  the  rapid  wearing  and  noisy 
acting  single-cylinder  motors  of  the  foreign  vertical  type. 

When  a  single-cylinder  engine  is  employed  a  very  heavy  fly  wheel 
is  needed  to  carry  the  moving  parts  through  idle  strokes  necessary  to 
obtain  a  power  impulse.  For  this  reason  modern  designers  prefer  to 
use  more  than  one  cylinder,  and  the  tendency  is  to  produce  power  -by 
frequently  occurring  light  impulses  rather  than  by  a  smaller  number 
of  explosions  having  greater  force.  When  a  single-cylinder  motor 
is  employed  the  construction  is  heavier  than  is  needed  with  a  multiple- 


The  Modern  Gasoline  Automobile 


85 


cylinder  form.  Using  two  or  more  cylinders  conduces  to  steady  power 
generation  and  a  lessening  of  vibration.  Most  modern  motor  cars 
employ  four-cylinder  engines  because  a  power  impulse  may  be  secured 
twice  every  revolution  of  the  crank  shaft,  or  a  total  of  four-power 
strokes  during  two  revolutions.  The  parts  are  so  arranged  that  while 
the  charge  of  gas  in  one  cylinder  is  exploding,  those  which  come 
next  in  firing  order  are  compressing,  discharging  the  inert  gases  and 
drawing  in  a  fresh  charge  respectively.  When  the  power  stroke  is 


Piston 


Connecting    Rod — ! 


Fig.  34. — Sectional  View  of  Brush  Runabout  Motor,  a  Simple  Single-Cylinder 
Power  Plant  of  the  Vertical  Type,  Designed  to  Operate  at  High  Speeds. 

completed  in  one  cylinder,  the  piston  in  that  member  in  which  a 
charge  of  gas  has  just  been  compressed  has  reached  the  top  of  its 
stroke  and  when  the  gas  is  exploded  the  piston  is  reciprocated  and 
keeps  the  crank  shaft  turning.  When  a  four-cylinder  engine  is  used 
the  fly  wheel  is  much  lighter  than  that  of  the  single-cylinder  form. 
In  fact,  many  modern  four-cylinder  engines  developing  thirty  horse 
power  weigh  less  than  the  early  single-cylinder  forms  which  developed 
but  one-third  or  one-fourth  that  amount  of  energy. 


Single  Cylinder 


Two  Cylinder  Vertical 
Crankpins  on  Same  Plane 


Two  Cylinder,  Opposed 
Cranhpins  At  180  Degrees 


Fig.  35. — Diagrams  Illustrating  Sequence  of  Cycles  in  One-  and  Two-Cylinder 
Engines  Show  More  Uniform  Turning  Effort  on  Crank  Shaft  with  Two- 
Cylinder  Motors. 

86 


The  Modern  Gasoline  Automobile  87 

Describing  Sequence  of  Operations. — Referring  to  Fig.  35,  A,  the 
sequence  of  operation  in  a  single-cylinder  motor  can  be  easily  under- 
stood. Assuming  that  the  crank  shaft  is  turning  in  the  direction  of  the, 
arrow,  it  will  be  seen  that  the  intake  stroke  comes  first,  then  the  com- 
pression, which  is  followed  by  the  power  impulse,  and  lastly  the  exhaust 
stroke.  If  two  cylinders  are  used,  it  is  possible  to  balance  the  ex- 
plosions in  such  a  way  that  one  will  occur  each  revolution.  This  is 
true  with  either  one  of  two  forms  of  four-cycle  motors.  At  B,  a  two- 
cylinder  vertical  engine  using  a  crank  shaft  in  which  the  crank  pins  are 
on  the  same  plane  is  shown.  The  two  pistons  move  up  and  down  simul- 
taneously. Referring  to  the  diagram  describing  the  strokes,  and  as- 
suming that  the  outer  circle  represents  the  cycle  of  operations  in  one 
cylinder  while  the  inner  circle  represents  the  sequence  of  events  in  the 
other  cylinder,  while  cylinder  No.  1  is  taking  in  a  fresh  charge  of  gas, 
cylinder  No.  2  is  exploding.  When  cylinder  No.  1  is  compressing, 
cylinder  No.  2  is  exhausting.  During  the  time  that  the  charge  in 
cylinder  No.  1  is  exploded,  cylinder  No.  2  is  being  filled  with  fresh  gas. 
While  the  exhaust  gases  are  being  discharged  from  cylinder  No.  1, 
cylinder  No.  2  is  compressing  the  gas  previously  taken  in. 

The  same  condition  obtains  when  the  crank  pins  are  arranged  at 
one  hundred  and  eighty  degrees  and  the  cylinders  are  opposed,  as 
shown  at  C.  The  reason  that  the  two-cylinder  opposed  motor  is  more 
popular  than  that  having  two  vertical  cylinders  is  that  it  is  difficult 
to  balance  the  construction  shown  at  B,  so  that  the  vibration  will  not 
be  excessive.  The  two-cylinder  opposed  motor  has  much  less  vibra- 
tion than  the  other  form,  and  as  the  explosions  occur  evenly  and  the 
motor  is  a  simple  one  to  construct,  it  has  been  very  popular  in  the 
past  on  light  cars. 

To  demonstrate  very  clearly  the  advantages  of  multiple-cylinder 
engines  the  diagrams  at  Fig.  36  have  been  prepared.  At  A,  a  three- 
cylinder  motor,  having  crank  pins  at  one  hundred  and  twenty  degrees, 
which  means  that  they  are  spaced  at  thirds  of  the  circle,  we  have  a 
form  of  construction  that  gives  a  more  even  turning  than  that  pos- 
sible with  a  two-cylinder  engine.  Instead  of  one  explosion  per  revo- 
lution of  the  crank  shaft,  one  'will  obtain  three  explosions  in  two 
revolutions.  The  manner  in  which  the  explosion  strokes  occur  and 
the  manner  they  overlap  strokes  in  the  other  cylinder  is  shown  at  A. 


88  The  Modern  Gasoline  Automobile 

Assuming  that  the  cylinders  fire  in  the  following  order,  first  No.  1, 
then  No.  3,  and  last  No.  2,  we  will  see  that  while  cylinder  No.  1, 
represented  by  the  outer  circle,  is  on  the  power  stroke,  cylinder  No. 
3  has  completed  the  last  two-thirds  of  its  exhaust  stroke  and  has 
started  on  its  intake  stroke.  Cylinder  No.  2,  represented  by  the 
middle  circle,  during  this  same  period  has  completed  its  intake  stroke 
and  two-thirds  of  its  exhaust  stroke.  A  study  of  the  diagram  will 
show  that  there  is  an  appreciable  lapse  of  time  between  each  explosion. 
In  the  four-cylinder  engine  operation  which  is  shown  at  Fig.  36, 
B,  it  will  be  seen  that  the  power  strokes  follow  each  other  without 
loss  of  time,  and  one  cylinder  begins  to  fire  and  the  piston  moves 
down  just  as  soon  as  the  member  ahead  of  it  has  completed  its  power 
stroke.  In  a  four-cylinder  motor,  the  crank  pins  are  placed  at  one 
hundred  and  eighty  degrees,  or  on  the  halves  of  the  crank  circle.  The 
crank  pins  for  cylinder  No.  1  and  No.  4  are  on  the  same  plane,  while 
those  for  cylinders  No.  2  and  No.  3  also  move  in  unison.  The  diagram 
describing  sequence  of  operations  in  each  cylinder  is  based  on  a  firing 
order  of  one,  two,  four,  three.  The  outer  circle,  as  in  previous  in- 
stances, represents  the  cycle  of  operations  in  cylinder  one.  The  next 
one  toward  the  center,  cylinder  No.  2,  the  third  circle  represents  the 
sequence  of  events  in  cylinder  No.  3,  while  the  inner  circle  outlines 
the  strokes  in  cylinder  four.  The  various  cylinders  are  working  as 
follows : 


1. 

2. 

3. 

4. 

Explosion 

Compression 

Exhaust 

Intake 

Exhaust 

Explosion 

Intake 

Compression 

Intake 

Exhaust 

Compression 

Explosion 

Compression 

Intake 

Explosion 

Exhaust 

It  will  be  obvious  that  regardless  of  the  method  of  construction,  or 
the  number  of  cylinders  employed,  exactly  the  same  number  of  parts 
must  be  used  in  each  cylinder  assembly  and  one  can  conveniently  com- 
pare any  multiple-cylinder  power  plant  as  a  series  of  single-cylinder 
engines  joined  one  behind  the  other  and  so  coupled  that  one  will  de- 
liver power  and  produce  useful  energy  at  the  crank  shaft  where  the 
other  leaves  off.  The  same  fundamental  laws  governing  the  action 
of  a  single  cylinder  obtain  when  a  number  are  employed,  and  the 


Firing  Order  1,3,2 


Three  Cylinder,  Cranks  At  120 Degrees 


Firing  Order  1.2,4,3 


Four  Cylinder,  Cranks  At  180  Degrees 


First  Revolution  Second  Revolution 

780"          7gQ°  780°  750° 


3      4 


Fig.   36. — Diagrams   Demonstrating   Clearly   Advantages  which   Obtain   when 
Multiple-Cylinder  Motors  are  Used  as  Power  Plants. 


90  The  Modern  Gasoline  Automobile 

sequence  of  operation  is  the  same  in  all  members,  except  that  the 
necessary  functions  take  place  at  different  times.  If,  for  instance,  all 
the  cylinders  of  a  four-cylinder  motor  were  fired  at  the  same  time, 
one  would  obtain  the  same  effect  as  though  a  one-piston  engine  was 
used,  which  had  a  piston  displacement  equal  to  that  of  the  four 
smaller  members.  As  is  the  case  with  a  single-cylinder  engine  the 
motor  would  be  out  of  correct  mechanical  balance  because  all  the 
connecting  rods  would  be  placed  on  crank  pins  that  lie  in  the  same 
plane.  A  very  large  fly  wheel  would  be  necessary  to  carry  the  piston 
through  the  idle  strokes,  and  large  balance  weights  would  be  fitted 
to  the  crank  shaft  in  an  effort  to  compensate  for  the  weight  of  the 
four  pistons,  and  thus  reduce  vibratory  stresses  which  obtain  when 
parts  are  not  in  correct  balance.  , 

There  would  be  no  advantage  gained  by  using  four  cylinders  in 
this  manner,  and  there  would  be  more  loss  of  heat  and  more  power 
consumed  in  friction  than  in  a  qne-piston  motor  of  the  same  capacity. 
This  is  the  reason  that  when  four  cylinders  are  used  the  arrangement 
of  crank  pins  is  always  as  shown  at  Fig.  36,  B — i.  e.,  two  pistons  are 
up,  while  the  other  two  are  at  the  bottom  of  the  stroke.  "With  this 
construction,  we  have  seen  that  it  is  possible  to  string  out  the  explo- 
sions so  that  there  will  always  be  one  cylinder  applying  power  to  the 
crarik  shaft.  The  explosions  are  spaced  equally.  The  parts  are  in 
correct  mechanical  balance  because  two  pistons  are  on  the  upstroke 
while  the  other  two  are  descending.  Care  is  taken  to  have  one  set 
of  moving  members  weigh  exactly  the  same  as  the  other.  With  a 
four-cylinder  engine  one  has  correct  balance  and  continuous  applica- 
tion of  energy.  This  insures  a  smoother  running  motor  which  has 
greater  efficiency  than  the  simpler  one-,  two-,  and  three-cylinder  forms 
previously  described.  Eliminating  the  stresses  which-  would  obtain 
if  we  had  an  unbalanced  mechanism  and  irregular  power  application 
makes  for  longer  life.  Obviously  a  large  number  of  relatively  light 
explosions  will  produce  less  wear  and  strain  than  would  a  lesser  num- 
ber of  powerful  ones.  As  the  parts  can  be  built  lighter  if  the  explo- 
sions are  not  heavy,  the  engine  can  be  operated  at  higher  rotative 
speeds  than  when  large  and  cumbersome  members  are  utilized. 

The  six-cylinder  type  of  motor,  the  action  of  which  is  shown  at 
Fig.  36,  C,  is  superior  to  the  four-cylinder,  inasmuch  as  the  power 


The  Modern  Gasoline  Automobile  91 

strokes  overlap,  and  instead  of  having  two  explosions  each  revolution 
we  have  three  explosions.  The  conventional  crank-shaft  arrangement 
with  a  six-cylinder  engine  is  just  the  same  as  though  one  employed 
a  three-cylinder  crank  shaft,  having  very  wide  crank  pins  so  that  the 
two  connecting  rods  are  joined  to  each  crank  throw.  With  the  cranks 
arranged  as  outlined  at  Fig.  36,,  C,  the  firing  order  is  one,  five, 
three,  six,  two,  four.  The  manner  in  which  the  power  strokes  over- 
lap is  clearly  shown  in  the  diagram.  An  interesting  comparison  is 
also  made  in  the  small  diagram  in  the  upper  left-hand  corner  of  this 
view. 

A  rectangle  is  divided  into  four  columns ;  each  of  these  correspond 
to  one  hundred  and  eighty  degrees,  or  half  a  revolution.  Thus  the 
first  revolution  of  the  crank  shaft  is  represented  by  the  first  two  col- 
umns, while  the  second  revolution  is  represented  hy  the  last  two. 
Taking  the  portion  of  the  diagram  which  shows  the  power  impulse  in 
a  one-cylinder  engine,  we  see  that  during  the  first  revolution  there 
has  been  no  power  impulse.  During  the  first  half  of  the  second  revo- 
lution, however,  an  explosion  takes  place  and  a  power  impulse  is  ob- 
tained. The  last  portion  of  the  second  revolution  is  devoted  to  ex- 
hausting the  burned  gases,  so  that  there  are  three  idle  strokes  and  but 
one  power  stroke.  The  effect  when  two  cylinders  are  employed  is 
shown  immediately  below. 

Here  we  have  one  explosion  during  the  first  half  of  the  first  revo- 
lution in  one  cylinder  and  another  during  the  first  half  of  the  second 
revolution  in  the  other  cylinder.  With  a  four-cylinder  engine  there 
is  an  explosion  each  half  revolution,  while  in  a  six-cylinder  engine 
there  is  one  and  one-half  explosions  during  each  revolution.  When  six 
cylinders  are  used  there  is  no  lapse  of  time  between  power  impulses, 
as  these  overlap  and  a  continuous  and  smooth-turning  movement  is 
imparted  to  the  crank  shaft.  While  the  six-cylinder  engine  has  ob- 
vious advantages,  it  will  be  evident  that  it  must  be  fifty  per  cent  more 
complicated  than  the  four-cylinder,  and  as  one  obtains  a  smooth- 
acting  engine  with  the  lesser  number,  the  majority  of  engineers  favor 
the  four-cylinder  type  of  power  plant  for  general  service. 

Actual  Duration  of  Different  Strokes. — In  the  diagrams  presented 
at  Figs.  35  and  36,  the  writer  has  assumed,  for  the  sake  of  simplicity, 
that  each  stroke  takes  place  during  half  of  one  revolution  of  the 


92 


The  Modern  Gasoline  Automobile 


crank  shaft,  which  corresponds  to  a  crank-pin  travel  of  one  hundred 
and  eighty  degrees.  The  actual  duration  of  these  strokes  is  somewhat 
different.  For  example,  the  inlet  stroke  is  usually  a  trifle  more  than 
a  half  revolution,  and  the  exhaust  is  always  considerably  more.  The 


Inlet  Value 
Opens  1%'Past 
Center-Upper^ 


Exhaust  Valve 
Closes      '  Past 


Inlet  Value 
Closes  5  %'Past 
Center-Lower 


Exhaust  Value 
Opens  7"Before 
Center-Lower 


Fig.  37. — Diagram  Showing  Actual  Duration  of  Different  Strokes  in  Degrees. 

diagram  showing  the  comparative  duration  of  the  strokes  is  shown 
at  Fig.  37.  The  inlet  valve  opens  ten  degrees  after  the  piston  starts 
to  go  down  and  remains  open  thirty  degrees  after  the  piston  has 
reached  the  top  of  its  stroke.  This  means  that  the  suction  stroke  cor- 
responds to  a  crank-pin  travel  of  two  hundred  degrees,  while  the  com- 


The  Modern  Gasoline  Automobile 


93 


pression  stroke  is  measured  by  a  movement  of  but  one  hundred  and 
sixty  degrees.  It  is  common  practice  to  open  the  exhaust  valve  before 
the  piston  reaches  the  end  of  the  power  stroke  so  that  the  actual  dura- 
tion of  the  power  stroke  is  about  one  hundred  and  forty  degrees, 
while  the  exhaust  stroke  corresponds  to  a  crank-pin  travel  of  two 
hundred  and  twenty-five  degrees.  In  this  diagram,  which  represents 
proper  time  for  the  valves  to  open  and  close,  the  dimensions  in  inches 
given  are  measured  on  the  fly  wheel  and  apply  only  to  the  "  Model  M  " 
Thomas  motor.  If  the  fly  wheel  were  smaller  ten  degrees  would  take 
up  less  than  the  dimensions  given,  while  if  the  fly  wheel  was  larger 
a  greater  space  on  its  circumference  would  represent  the  same  crank- 
pin  travel. 


Carburetor 


Spark  Plug 


Value 


Cylinder 


Connecting  Rod 


Crankshaft 


Piston 
Flywheel 


Fig.  38. — Simple  Form  of  Two-Cylinder  Motor  Having  Opposed  Cylinders;  a 
Very  Popular  Form  of  Power  Plant  for  Light  Service. 

^  Typical  Engine  Types  Described. — A  very  simple  and  efficient  type 
of  power  plant  is  shown  at  Fig.  38.  In  this  motor  the  cylinders  are 
horizontally  disposed  and  opposed  to  each  other.  The  valves  are  car- 
ried in  a  pocket,  or  chamber,  on  top  of  the  cylinder  and  they  are  oper- 
ated by  direct  push-rod  movement  from  a  cam  shaft  carried  just 
above  the  crank  shaft.  The  general  arrangement  of  parts  is  clearly 


94 


The  Modern  Gasoline  Automobile 


outlined,  and  as  each  component  is  indicated  there  should  be  no  diffi- 
culty in  grasping  the  details  of  this  form  of  power  plant.  The  motor 
illustrated  at  Fig.  39  is  a  simple  four-cylinder  type  of  modern  con- 
struction and  may  be  considered  representative  of  standard  practice. 
In  this  motor  it  will  be  seen  that  the  four  cylinders  are  arranged  on 
a  crank  case  common  to  them  all.  The  crank  case  also  acts  as  a  sup- 
porting member  for  the  crank  shaft  and  cam  shaft.  A  section  of  the 
crank  case  is  broken  away  to  show  the  crank-shaft  design,  and  also 
to  illustrate  the  method  employed  of  raising  the  valves  from  their 


Engine  Base 


Fig.  39.— Sectional  View  of  Four-Cylinder  Motor,  the  Most  Widely  Used  Type 

of  Multiple  Engine. 

seats  by  means  of  cams.  The  front  cylinder  is  not  sectioned.  The 
second  cylinder,  which  is  immediately  back  of  it,  is  sectioned  through 
the  valve  chest  in  order  to  show  the  gas  passages  and  the  method  of 
closing  them  by  mushroom  valves.  Cylinder  No.  3  is  divided  on  its 
center  line  to  show  the  piston  and  connecting  rod  assembly,  while  the 
last  cylinder  is  sectioned  in  such  a  way  that  the  construction  of  the 
piston,  connecting  rod,  and  wrist  pin  is  clearly  shown. 

Another  type  of  four-cylinder  engine  sectioned  in  a  somewhat 
similar  manner  with  all  parts  indicated  is  shown  at  Fig.  40.     A 


95 


96 


The  Modern  Gasoline  Automobile 


careful  study  of  this  illustration  should  familiarize  one  with  the  gen- 
eral arrangement  of  the  parts  of  conventional  power  plants.  The 
views  shown  at  Figs.  39  and  40  are  longitudinal  sections.  In  order 


Exhaust  Valve 
Exhaust  Pipe 


Water  Pipe 

Water  Space 


Inlet  Value 


Inlet  Pipe 


Magneto 


\ 

Carburetor 


Fig.  41. — Sectional  View  of  Rear  Cylinder  of  Gasoline  Engine  with  Important 

Parts  Indicated. 

to  show  the  appearance  of  the  parts  of  an  engine  when  one  of  the 
cylinders  is  cut  in  such  a  manner  that  it  is  viewed  from  the  end 
rather  than  from  the  side,  such  a  section  is  given  at  Fig.  41.  As  is 
the  case  in  other  illustrations  all  parts  are  clearly  indicated.  This 


The  Modern  Gasoline  Automobile  97 

view  is  also  valuable  in  showing  the  arrangement  of  some  of  the  aux- 
iliary components,  such  as  the  water  pump,  which  is  used  to  circulate 
the  cooling  liquid;  the  carburetor,  which  is  employed  to  furnish  the 
explosive  mixture;  and  the  magneto,  which  is  supplied  to  ignite  the 
compressed  gas.  The  exhaust  pipe,  which  is  attached  to  the  side  of 
the  cylinder  to  carry  away  the  burned  gases,  and  the  sump,  or  oil  con- 
tainer, which  carries  a  supply  of  the  lubricant  to  keep  the  working 
surfaces  free,  are  also  outlined. 

.  Features  of  the  Knight  Slide  Valve  Motor. — One  of  the  latest  ten- 
dencies of  engineers  responsible  for  the  design  of  motor-car  power 
plants  is  toward  the  elimination  of  all  noises  incidental  to  their  opera- 
tion. Much  of  this  has  been  attributed  to  operation  of  the  valves  and 
in  order  to  reduce  the  clatter,  types  of  engines  in  which  the  poppet,  or 
mushroom,  valves  are  replaced  by  sliding  or  revolving  elements  are 
being  extensively  experimented  with. 

The  earliest  types  of  explosion  motors,  as  evolved  by  Lenoir,  Bray- 
ton,  and  Otto,  employed  simple  slide  valves  which  were  patterned 
after  those  used  in  steam  engines.  Owing  to  faulty  construction  these 
early  forms  were  not  successful,  as  considerable  difficulty  was  expe- 
rienced from  warping  and  in  keeping  the  cylinder  tight  enough  to 
retain  gas  pressure.  In  several  engines  of  recent  development  the 
mushroom  valves  are  being  replaced  by  sleeves  which  have  a  more 
gradual  motion  and  which  slide  by  ports  in  the  cylinder  instead  of 
being  brought  forcibly  in  contact  with  the  seats  by  a  strong  spring. 
An  advantage  of  the  slide  valve  motor,  which  is  perhaps  even  more 
important  than  that  of  silence,  is  the  increased  flexibility  and  aug- 
mented power  developed,  because  the  large  gas  passages  permit  the 
entering  stream  of  fresh  vapor,  or  the  departing  current  of  inert  gas 
to  leave  the  cylinder  without  being  impeded.  The  disadvantage  often 
cited  against  poppet  valves  is  that  at  high  speeds  they  fail  to  follow 
the  contour  of  their  actuating  cams  accurately  and  there  is  consider- 
able loss  of  power  because  of  the  irregular  gas  flow. 

The  most  practical  and  satisfactory  of  the  valveless  motors  now  in 
use  was  invented  by  Charles  Y.  Knight,  an  American  engineer,  sev- 
eral years  ago.  When  first  introduced  in  this  country  it  was  met  with 
considerable  ridicule,  and  the  inventor  was  forced  to  take  his  inven- 
tion to  Europe,  where  its  advantages  met  with  prompt  recognition. 


98 


The  Modern  Gasoline  Automobile 


Fig.  42.— Comparing  Poppet  Valve  and  Sliding  Sleeve  Valve  Power  Plants. 
Upper  View  Shows  Knight  Engine  with  Sleeves  to  Control  Gas  Ports. 
Lower  Illustration  Shows  Gas  Passages  Controlled  by  Mushroom  Valves. 


The  Modern  Gasoline  Automobile  99 

The  Knight  valveless  motor  is  now  made  and  used  by  such  celebrated 
automobile  manufacturers  as,  Daimler,  in  England;  Panhard-Levas- 
sor,  in  France;  Minerva,  in  Belgium;  and  Mercedes,  in  Germany.  In 
this  country  it  will  be  found  on  models  of  the  Columbia,  Stearns,  and 
Stoddard-Dayton. 

The  operating  principles  in  this  engine  do  not  differ  materially 
from  other  four-cylinder,  four-cycle  types,  the  only  difference  being  in 
the  method  of  admitting  and  expelling  gases  from  the  cylinder/  The 
illustrations  at  Fig.  42  show  very  clearly  the  difference  which  exists 
between  the  slide  valve  and  the  conventional  poppet  valve  motor. 
Both  of  these  are  the  same  in  general  design,  except  that  changes 
have  been  made  in  the  power. plant  to  permit  the  use  of  reciprocating 
sleeves.  The  upper  illustration  represents  the  slide  valve  motor  in 
part  section,  while  the  lower  view  shows  the  conventional  poppet  valve 
type. 

The  Knight  motor  has  four  cylinders  cast  in  pairs.  The  top  of 
each  cylinder  has  two  lateral  slots  which  communicate  respectively 
with  the  inlet  and  exhaust  pipes.  The  cylinder  is  water- jacketed, 
and  inside  of  this  member  and  interposed  between  it  and  the  piston 
are  two  thin,  hollow  cast-iron  cylinders,  or  sleeves,  adapted  to  be 
moved  up  and  down  by  a  suitable  crank  shaft  and  connecting  rod 
mechanism  or  eccentrics.  These  sleeves  have  large  ports  which  com- 
municate with  the  orifices  in  the  cylinder  wall.  They  are  moved  in 
such  a  manner  that  the  slots  in  the  cylinder  are  opened  and  closed 
by  the  reciprocating  movement  of  the  sleeves.  They  are  operated 
by  small  connecting  rods  which  work  from  a  smaller  crank  shaft 
mounted  to  one  side  of,  and  above  the  main  crank  shaft,  and  driven 
by  silent  chain  gearing.  The  travel  of  the  sleeves  is  comparatively 
small,  as  their  velocity  is  but  one-tenth  that  of  the  piston.  The  open- 
ings in  the  sleeves  are  so  wide  that  the  gases  enter  and  leave  the 
combustion  chamber  much  more  easily  than  they  could  through  ports 
closed  by  yalves  of  the  conventional  type. 

The  movement  of  the  sleeves  is  such  that  the  ports  in  the  cylinder 
are  closed  by  one  or  both  sleeves  during  three-quarters  of  the  cycle 
of  operation,  and  are  kept  open  during  the  remaining  quarter  by  a 
simultaneous  lining  up  of  the  openings  in  both  sleeves  with  that  in 
the  cylinder.  As  is  the  case  with  a  four-cycle  motor  of  the  conven- 


QQ 


100 


The  Modern  Gasoline  Automobile  101 

tional  pattern  during  the  first  downstroke  of  the  piston  the  inlet 
port  is  opened  and  the  exhaust  orifice  closed.  During  the  next  two 
piston  strokes,  one  up  and  the  other  down,  corresponding  to  the  com- 
pression and  explosion  of  the  gas,  both  ports  are  kept  closed.  Then 
during  the  last  upstroke,  which  corresponds  to  the  scavenging  period, 
the  exhaust  port  is  opened  and  the  inlet  port  closed. 

It  is  claimed  that  this  motor  is  very  silent  at  high  speeds,  and  it 
is  more  flexible  in  operation  than  other  forms.  It  is  also  said  that 
this  type  of  motor  will  retain  its  compression  longer  than  the  poppet 
valve  type,  because  there  can  be  no  escape  of  gas  through  the  ports 
when  they  are  closed  by  the  sleeves.  The  moving  members  are  lubri- 
cated in  the  usual  manner,  the  only  precaution  taken  being  to  insure 
an  even  distribution  of  oil  by  cutting  a  spiral  groove  and  boring  a 
number  of  holes  in  each  sleeve.  The  great  advantage  of  this  type 
over  the  poppet  valve  motor  can  be  very  well  shown  by  comparing  the 
illustrations  at  Figs.  43  and  44,  which  show  action  of  the  valves  used 
on  the  ordinary  motor  with  the  views  at  Figs.  46  and  47.  At  Fig.  43, 
A,  the  position  of  the  piston,  crank  shaft,  cam,  and  intake  valve  are 
shown  at  the  beginning  of  the  charging  stroke.  It  will  be  noticed 
that  the  intake  valve  has  just  barely  left  its  seat  and  that  there  will 
be  little  space  for  the  gases  to  flow  into  the  cylinder  until  the  piston 
lias  reached  the  position  shown  at  Fig.  43,  B,  at  which  point  the  inlet 
valve  is  fully  opened.  From  this  point  to  that  outlined  at  Fig.  43,  C, 
the  inlet  valve  closes  and  the  gas  passage  becomes  more  and  more 
restricted  as  the  piston  travels  down.  The  same  condition  obtains 
when  the  exhaust  valve  is  operated.  It  lifts  gradually,  and  the  full 
opening  is  not  attained  until  the  parts  have  assumed  the  position 
shown  at  Fig.  44,  B.  From  this  point  to  that  outlined  at  Fig.  44,  C, 
the  valve  is  closing.  It  will  be  evident  that  with  mushroom  valves 
one  attains  the  maximum  port  opening  only  during  the  time  that 
the  cam  follower  rides  on  the  point  of  the  cam  which  is  but  an  instant. 
The  cam  roller  follows  the  cam  profile  only  at  low  and  moderate 
speeds.  When  the  velocity  increases  the  cam  will  throw  the  push 
rod  instead  of  lifting  it  and  the  action  will  be  erratic.  Incidentally, 
these  views  show  very  clearly  the  method  of  valve  operation  and  will 
prove  valuable  in  assisting  the  reader  to  gain  an  idea  of  valve  timing 
which  will  be  discussed  at  length  in  proper  sequence. 


102 


The  Modern  Gasoline  Automobile 


103 


The  view  at  Fig.  45  is  a  simplified  section  which  shows  the  parts 
of  the  Knight  type  motor  to  advantage.  The  diagrams  at  Figs.  46 
and  47  will  enable  the  reader  to  see  the  relation  of  the  sleeves  at  dif- 
ferent points  in  the  cycle  of  opera- 
tion. At  Fig.  46,  A.,  the  position 
at  the  inception  of  the  intake 
stroke  is  clearly  shown.  At  B  the 
parts  have  assumed  positions  that 
permit  the  fresh  gas  to  flow 
quickly  into  the  cylinder.  At  C 
the  sleeves  are  closed.  It  will  be 
apparent  that  one  obtains  a  clear 
port  through  which  the  gases  may 
flow  easily  as  soon  as  the  intake 
stroke  begins.  This  is  increased 
in  value  until  the  maximum  open- 
ing is  reached,  just  as  with  a  pop- 
pet valve.  The  important  point 
to  observe,  however,  is  that  there 
is  always  a  straight  passage  for 
the  gas  to  flow  through  while  the 
port  is  open.  Even  when  the  pop- 
pet valve  has  been  raised  to  the 
highest  point  there  is  still  diffi- 
culty for  the  gas  to  leave  the 
cylinder  because  of  the  tortuous 
passage  and  the  number  of  turns 
the  gas  stream  must  make  to  enter 
and  leave  the  combustion  chamber. 
Fig.  47  depicts  the  movement  of 
the  sliding  sleeve  valves  on  the  ex- 
haust stroke. 

In  order  to  obtain  uniform 
power  application  and  a  smooth 
running  engine  it  is  essential  that 
the  gases  in  each  cylinder  be  com- 
pressed to  the  same  value  before 


Fig.  45.— End  Sectional  View  of  Knight 
Sliding  Sleeve  Type  Motor,  Show- 
ing Sleeves  which  Take  Place  of  the 
Poppet  Valves  of  Conventional  Mo- 
tors. A— Outer  Valve  Shell,  fi- 
lmier Valve  Shell.  C — Operating 
Lever  for  A.  D — Operating  Lever 
for  B.  E — Lay  Shaft.  F— Crank 
Shaft.  G  —  Helical  Gears.  H  — 
Valve  Opening.  K — Cylinder  Head. 
L  —  Sparking  Plug  Holes.  O  — 
Cross -Shaft  Driving  Pump  and 
Magneto.  U — Piston. 


104  The  Modern  Gasoline  Automobile 

ignition  takes  place.  If  the  compression  is  less  in  one  cylinder  then 
that  member  will  be  doing  less  work  than  the  others  and  the  rotative 
speed  will  not  be  constant.  The  crank  shaft  will  slow  up  when  it 
comes  to  the  weak  cylinder,  and  will  accelerate  when  the  three  strong 
ones  are  acting  on  it.  It  is  claimed  that  in  the  Knight  motor  the 
absolute  constancy  of  compression  makes  for  uniformity  of  action 
because  the  intervals  between  the  successive  explosions  are  always 
equal  and  all  of  the  power  strokes  have  the  same  strength.  It  is  also 
advanced  that  the  construction  of  the  Knight  motor  makes  it  possible 
to  obtain  combustion  chambers  which  are  equal  in  volume,  which  con- 
dition is  difficult  to  attain  with  the  ordinary  construction,  because  of 
the  difficulty  met  in  securing  perfect  equality  of  castings.  As  the 
cylinders  and  cylinder  heads  of  the  Knight  motor  are  .machined  to 
the  required  dimensions  and  polished,  all  combustion  chambers  will 
have  the  same  volume.  Another  advantage  is  that  there  will  be  no 
projecting  particles  of  metal  such  as  would  be  present  in  castings  that 
might  remain  hot  and  cause  premature  explosions.  It  is  also  difficult 
for  carbon  to  adhere  to  the  absolutely  smooth  walls  of  the  combustion 
chamber  or  piston  head. 

There  is  very  little  strain  on  the  parts,  and  as  the  wear  of  the 
sleeves  is  negligible  the  motor  action  improves  with  service,  because 
the  sleeves  become  polished  and  work  easier  the  more  they  are  usec\. 
As  the  sleeves  are  driven  by  cranks  and  connecting  rods  and  not  by 
cams  as  poppet  valves  are,  they  are  not  liable  to  go  wild  at  even  the 
highest  motor  speeds.  The  ports,  are  opened  and  closed  exactly  at 
the  proper  time,  and  the  openings  or  passages  for  the  gas  are  so 
large  that  the  motor  capacity  augments  with  an  increase  of  speed. 

In  a  comparative  test  of  two  similar  motors,  one  with  mushroom 
valves  and  the  other  with  sleeves,  the  former  developed  but  twenty- 
five  horse  power  at  2,000  revolutions  per  minute,  while^tfe  sleeve 
type  generated  in  excess  of  thirty  horse  power  'under  the  same  con- 
ditions. The  Knight  motor  has  been  subjected  to  severe  tests  before 
adoption  in  comparison  with  motors  of  the  poppet  valve  type.  In 
one  of  these  an  engine  rated  at  thirty-eight  horse  power  which  had 
cylinders  of  5-inch  bore  and  stroke  developed  55.3  horse  power  con- 
tinuously during  a  period  of  5l/2  days,  or  132  hours.  The  fuel  con- 
,  sumption  was  but  0.85  pint  of  gasoline  per  horse  power  hour.  The 


The  Modern  Gasoline  Automobile  105 

average  fuel  consumption  of  the  four-cycle  type  of  motor  is  placed 
at  one  pint  per  horse  power  hour.  At  the  completion  of  this  running 
in  test  the  power  plant  was  installed  in  a  car  weighing  4,000  pounds. 
This  was  driven  over  2,000  miles  on  Brooklands  Motor  Track,  near 
London,  England,  at  a  speed  which  averaged  forty-three  miles  per 
hour.  At  the  completion  of  this  test  the  motor  was  replaced  on  a 
test  stand  in  the  shop  where  it  developed  an  average  of  57.25  horse 
power  during  a  run  of  five  hours  at  1,200  revolutions  per  minute. 
The  fuel  consumption  was  reduced  to  0.75  pint  of  gasoline  per  horse 
power  hour  and  it  had  gained  two  horse  power,  or  about  four  per  cent 
by  use. 

This  type  of  valveless  motor  is  considered  to  be  an  improvement 
over  the  conventional  forms,  and  it  is  all  the  more  strange  when  one 
considers  that  the  height  of  its  development  has  been  reached  at  a  time 
when  all  believed  the  explosion  motor  had  attained  its  maximum 
efficiency.  The  success  attending  the  use  of  the  Knight  motor  has 
promoted  great  interest  in  all  forms  of  valveless  motors  which  are 
being  actively  experimented  with  at  the  present  time.  Some  of  the 
most  successful  of  these  types  will  be  described  in  detail  in  the  fol- 
lowing chapters. 

Operating  Principles  of  Two-Cycle  Engines. — While  the  majority 
of  automobiles  use  four-cycle  internal  combustion  engines  for  propul- 
sion there  are  cases  where  the  simpler  two-stroke  cycle  motor  has  been 
used.  Though  it  has  been  widely  used  in  marine  applications  for 
years  it  has  not  become  very  popular  in  motor-car  service.  If  con- 
sidered from  a  theoretical  point  of  view  the  two-cycle  engine  has 
important  advantages,  and  if  ideal  conditions  were  obtained  in  practice, 
motors  of  this  type  would  develop  twice  the  amount  of  power  obtain- 
able from  four-cycle  engines  having  the  same  number  of  cylinders, 
equal  piston  displacement  and  operating  at  the  same  crank  shaft 
speed. 

The  two-cycle  motor  is  much  simpler  than  the  other  forms,  and  it 
has  but  three  moving  ports  per  cylinder.  In  this  type  a  power  im- 
pulse is  obtained  with  each  downstroke  of  the  piston  instead  of  every 
other  downstroke.  With  the  explosion  occurring  twice  as  often  the 
energy  delivered  is  increased  in  direct  proportion  and  a  more  even 
turning  movement  of  the  crank  shaft  results  because  of  the  more 


106  The  Modern  Gasoline  Automobile 

rapid  series  of  explosions.  It  has  been  shown  that  with  the  four- 
stroke  engine  three  operations  are  necessary  to  obtain  a  useful  power 
impulse.  The  first  downward  movement  of  the  piston  dfaws  in  the 
gas.  The  following  upward  movement  compresses  the  mixture.  The 
second  down  movement  of  the  piston  takes  place  during  the  expan- 
sion or  explosion  stroke,  and  is  the  third  and  power-producing  part 
of  the  cycle.  Following  this  operation  the  remaining  stroke  of  the 
piston,  which  is  upward,  clears  the  cylinder  of  burned  gas. 

Obviously  all  the  work  is  done  at  the  -top  of  the  piston,  and  the 
differing  functions  take  place  in  the  combustion  chamber  or  that  por- 
tion of  the  cylinder  above  the  piston.  With  a  two-cycle  engine  all 
this  work  can  be  accomplished  in  half  the  number  of  strokes,  and  it 
is-  possible  to  secure  an  explosion  stroke  after  each  idle  stroke.  There 
is  a  power  impulse  every  revolution  of  the  crank  shaft  for  each  cylin- 
der instead  of  every  two  turns,  and  energy  is  created  every  two  strokes 
of  the  piston.  To  accomplish  this,  work  is  performed  on  both  sides  of 
the  piston,  as  the  crank  case  is  utilized  as  well  as  the  part  of  the 
cylinder  above  the  piston.  The  top  of  this  member  compresses  the 
charge  and  receives  the  pressure  of  the  explosion,  as  these  two  essential 
functions  can  only  take  place  in  that  portion  of  the  cylinder  above 
the  piston.  The  crank  case  performs  the  duty  of  the  inspiration 
stroke,  as  the  mixture  is  drawn  into  the  engine  base  by  the  upwardly 
moving  piston.  This  is  done  at  the  same  time  that  the  piston  is  mov- 
ing up  to  compress  the  gas  above  it,  previously  taken  in.  The  views 
at  Fig.  48  show  the  principles  of  operation  of  two-port,  two-cycle 
engines,  while  those  at  Fig.  49  define  the  fundamentals  of  three-port 
two-cycle  engine  operation.  The  principle  in  the  main  is  the  same 
for  both  types,  the  only  difference  being  in  the  method  of  introducing 
the  gas  to  the  crank  case. 

It  will  be  seen  that  such  engines  are  very  simple,  and  that  the 
pistons,  connecting  rods,  and  crank  shaft  are  the  only  moving  parts. 
Instead  of  valves  and  operating  mechanism  to  control  the  gas  flow  by 
ports,  or  passages  which  are  cast  in  the  cylinder  walls  about  halfway 
down  their  length  are  used.  The  gas  is  taken  into  the  engine  base, 
which  is  air  tight,  and  of  small  capacity ;  in  one  case  through  an  auto- 
matic check  valve  fitting  to  which  the  carburetor  is  attached.  In  the 
three-port  form  this  valve  is  eliminated  and  the  carburetor  is  coupled 


& 

V 

u 


3 


107 


108  The  Modern  Gasoline  Automobile 

directly  to  the  cylinder.  The  gas  is  transferred  from  the  crank  case 
to  the  cylinder  through  a  bypass,  or  a  passage  leading  from  the 
engine  base  to  the  intake  port. 

Considering  first  the  action  of  the  two-port,  two-cycle  type  it  will 
be  evident  that  if  the  base  is  air  tight  an  upward  movement  of  the 
piston  will  produce  a  suction  in  the  engine  base,  drawing  the  inlet 
valve  down  from  its  seat  and  inspiring  a  mixture  of  gasoline  and  air 
from  the  carburetor.  Thus  when  the  piston  moves  up,  the  engine 
base  fills  with  vapor.  On  the  down  movement  of  the  piston  the  gas 
in  the  crank  case  is  compressed,  and  when  the  top  of  the  piston  reg- 
isters with  the  inlet  port  in  the  side  of  the  cylinder  the  mixture  will 
transfer  to  the  cylinder  above  the  piston  because  of  its  pressure.  The 
intake  port  is  opened  as  the  piston  side  uncovers  it.  The  compres- 
sion in  the  engine  base  is  light  compared  to  that  above  the  piston. 
While  the  compression  pressure  before  ignition  may  be  as  high  as 
eighty  pounds  per  square  inch,  that  in  the  engine  base  necessary  to 
insure  prompt  transfer  of  the  charge  seldom  exceeds  ten  pounds.  The 
operation  of  this  type  engine  is  not  difficult  to  understand. 

Eeferring  to  Fig.  48,  A,  we  will  assume  that  there  is  a  compressed 
charge  of  gas  above  the  top  of  the  piston,  and  that  the  crank  case  is 
full  of  mixture.  The  spark  occurs  at  the  spark  plug  and  the  resulting 
explosion  forces  the  piston  down  on  its  power  stroke,  this  movement 
also  compressing  the  gas  already  in  the  engine  base.  When  the  piston 
uncovers  the  exhaust  port  it  begins  to  open  before  the  intake  port  is 
uncovered  and  the  burned  gases  escape  to  the  air  because  of  their 
pressure.  After  the  exhaust  port  has  been  open  for  a  small  period 
the  inlet  port  is  uncovered  by  the  piston  which  is  still  on  its  downward 
movement.  The  compressed  gas  in  the  case  flows  through  the  bypass 
and  into  the  cylinder.  It  cannot  escape  out  of  the  open  exhaust  port 
opposite,  because  the  deflector  directs  the  gases  toward  the  top  of 
the  cylinder.  The  fresh  gas  coming  in  tends  to  force  out  any  of  the 
burned  residue  which  tends  to  remain.  As  the  piston  rises  on  the 
return  stroke  Tboth  ports  are  closed  and  the  gas  in  the  cylinder  is  com- 
pressed. Simultaneously  with  the  gas  compression  the  partial  vacuum 
created  in  the  engine  base  draws  in  new  mixture  from  the  carburetor 
through  the  open  check  valve. 

Three-port  engine  operation,  as  shown  at  Fig.  49,  is  very  similar 


J09 


110  The  Modern  Gasoline  Automobile 

to  that  previously  described,  except  that  the  intake  port  in  the  cylin- 
der to  which  the  carburetor  is  coupled  is  uncovered  by  the  piston  only 
when  it  has  traveled  up  in  the  cylinder.  There  is  a  pronounced 
vacuum  in  the  crank  case  when  this  port  is  uncovered  and  the  rapid 
rush  of  gas  insures  quick  charging.  The  three-port  engine  is  con- 
siderably faster  than  the  two-port  type,  and  is  more  popular  for  motor- 
car service.  In  the  three-port  form  of  engine  the  mixture  rushes  in 
to  fill  the  engine  base  as  a  body,  whereas  in  the  two-port  type  it  is 
drawn  in  gradually  during  the  whole  upstroke  of  the  piston. 

If  the  reader  compares  the  views  of  the  simple  two-cycle  engines 
shown,  with  the  four-cycle  types  previously  described,  it  will  be  seen 
that  the  former  are  simpler.,  because  many  of  the  small  parts  necessary 
for  the  successful  action  of  a  four-stroke  motor  are  not  needed  in 
the  two-stroke  motor.  The  valves  and  operating  mechanism  are  dis- 
pensed with,  which  means  elimination  of  the  cam  shafts,  driving  gear- 
ing, cams,  and  push  rods,  incidental  to  valve  operation.  As  the  cylin- 
der of  the  two-cycle  engine  is  charged  and  cleaned  through  simple 
ports  which  are  but  orifices  left  after  cutting  away  part  of  the  cylinder 
wall,  the  gas  can  be  introduced  and  discharged  with  much  less  mech- 
anism. The  ports  are  covered  by  the  piston  until  the  time  comes 
when  they  are  needed.  In  the  two-port  form  both  openings  are 
opened  fully  only  when  the  piston  reaches  the  end  of  the  downstroke, 
but  in  the  three-port  motor  the  remaining  opening  through  which  the 
crank  case  is  charged  is  uncovered  when  the  piston  reaches  the  end 
of  its  upward  movement. 

The  simple  forms  of  two-cycle  motors  described  have  been  replaced 
in  some  cases  by  types  in  which  the  preliminary  compression  of  gas 
in  the  crank  case  has  been  eliminated.  This  is  accomplished  by  the 
use  of  a  two-diameter  piston,  as  shown  at  Fig.  50.  The  cylinder 
proper  consists  of  an  upper  and  lower  chamber.  The  small  portion 
of  the  piston  fits  the  upper  c}dinder  while  the  enlarged  part  fits  the 
lower  end.  Instead  of  the  gas  being  inspired  into  the  engine  base 
it  is  drawn  into  the  enlarged  portion  of  the  cylinder.  It  has  been  dim- 
cult  to  maintain  regularity  of  two-cycle  motor  action  when  crank  case 
compression  was  used,  because  any  leakage  at  the  bearings,  or  pack- 
ings in  the  crank  case,  meant  a  reduction  in  vacuum  and  made  for 
uncertain  charging. 


The  Modern  Gasoline  Automobile 


111 


With  the  construction  outlined  at  Fig.  50,  the  gas  is  taken  into 
the  large  portion  of  the  main  cylinder,  and  as  the  pumping  piston 
is  provided  with  packing  rings  just  as  the  working  piston  is,  it  is 
not  difficult  to  keep  a  tight  charging  chamber.  The  positions  of  the 
pistons  in  the  various  cylinders  of  a  four-cylinder  motor  using  a  dif- 
ferential piston  arrangement  are  shown  at  Fig.  50.  It  will  be  seen  that 
a  rotary  distributing  valve  must  be  used  to  permit  the  gas  to  enter 
the  pump  cylinder  and  flow  into  the  working  cylinder  at  the  right 
time;  this  is  turned  by  gearing  from  the  crank  shaft. 


Fig.  50. — Explaining  Action  of  Differential  Piston  Type  of  Two-Cycle  Engine. 

At  A  the  piston  is  going  up  and  a  charge  of  gas  is  being  com- 
pressed in  both  the  working  cylinder  and  the  pump  cylinder.  At 
B,  which  represents  the  section  through  cylinder  No.  2,  the  piston  is 
moving  down  under  the  influence  of  the  explosion  and  the  pumping 
piston  is  drawing  in  a  charge  of  gas  through  the  distributing  valve 
which  is  in  communication  with  the  inlet  pipe.  At  C  a  section 
through  cylinder  No.  3  is  shown.  The  working  piston  in  this  case 
has  reached  the  top  of  its  stroke  and  is  ready  to  receive  the  impact 
due  to  the  explosion  of  the  charge.  At  D  a  section  through  cylinder 
No.  1  is  outlined.  The  cylinder  valve  has  made  communication  with 
the  pumping  chamber  of  cylinder  No.  3,  as  shown  at  C,  and  a  charge 
of  gas  is  being  transferred  to  the  working  cylinder  No.  1.  The 
burned  gases  are  expelled  through  the  open  exhaust  port  in  the  usual 
manner  and  admitted  by  the  customary  intake  port  adjacent  to  the 
deflector  plate.  The  action  in  this  type  of  engine  may  be  easily  un- 


112  The  Modern  Gasoline  Automobile 

derstood  if  one  considers  that  the  pumping  chamber  of  one  cylinder  is 
employed  to  draw  in  gas  and  compress  it  prior  to  transferring  it  to 
the  working  chamber  of  another  cylinder. 

«  Why  Two-Cycle  Motor  is  not  Widely  Used. — It  has  been  previously 
stated  that  the  four-cycle  motor  is  almost  universally  used,  and  to 
properly  understand  the  reason  for  the  preponderance  of  this  type 
over  the  simpler  two-cycle  forms  it  is  necessary  to  compare  the  actual 
results  obtained  from  the  two-stroke  motor  in  ordinary  practice  with 
the  advantages  a  purely  theoretical  consideration  will  give  it.  There 
are  a  number  of  problems  to  be  solved  before  the  two-cycle  motor  will 
compare  with  the  other  type  in  efficiency.  To  obtain  maximum  power 
it  is  necessary  that  a  full  charge  of  explosive  gas  enter  the  cylinder; 
that  this  mixture  must  be  properly  proportioned;  that  it  should  be 
compacted  to  a  certain  point  before  ignition,  and  that  it  must  be 
ignited  promptly  and  at  the  proper  time.  In  order  to  obtain  a  full 
charge  of  pure  mixture  it  is  evident  that  the  exhaust  gases  must  be 
entirely  expelled  from  the  cylinder  in  order  that  the  incoming  fresh 
gas  will  not  be  contaminated  by  mixing  with  the  dead  products  of 
combustion. 

It  is  much  more  difficult  to  secure  a  full  charge  of  clean  mixture 
with  a  two-cycle  engine  than  with  a  four-cycle.  In  the  former,  the 
charging  with  fresh  gases  and  expulsion  of  dead  gases  must  take  place 
in  half  the  time  allowed  in  the  latter  form,  and  the  piston  does  not 
pump  in  a  charge  or  force  the  burned  gases  out  of  the  cylinder,  as  is 
the  case  with  a  four-stroke  engine.  As  the  two-cycle  motor  does  not 
fully  expel  the  burned  products  it  cannot  run. as  fast  because  of  a 
tendency  to  choke  up  at  high  speeds.  In  the  four-cycle  engine  a  full 
stroke  of  the  piston  is  employed  in  emptying  the  cylinder,  and  the 
natural  gas  pressure  is  increased  by  the  reduction  of  cylinder  volume 
caused  by  the  upwardly  moving  piston. 

In  the  two-cycle  forms  the  burned  gas  is  discharged  through  the 
open  exhaust  port  by  its  own  pressure.  If  prompt  charging  and 
clearing  of  the  cylinder  was  the  only  problem  to  be  solved  in  securing 
efficient  action  it  would  not  be  difficult  to  provide  large  enough  ports 
to  attain  this  end.  The  port  size  must  be  restricted,  however,  and 
carefully  proportioned  because  as  both  intake  and  exhaust  passages 
are  uncovered  by  the  piston  at  practically  the  same  time  a  large  por- 


The  Modern  Gasoline  Automobile  113 

tion  of  the  incoming  gas  may  be  discharged  with  the  burned  product, 
this  making  for  a  large  fuel  consumption  and  material  reduction  of 
efficiency.  As  the  gas  is  not  perfectly  clean  and  pure,  some  difficulty 
may  be  experienced  in  igniting  it.  Trouble  is  also  experienced  with 
the  cooling,  lubrication,  and  carburetion  groups,  as  most  two-cycle 
motors  have  peculiarities  which  make  proper  oiling  and  gas  supply 
difficult. 

Most  automobile  designers  have  adopted  the  four-cycle  power 
plant,  because  it  has  been  perfected  to  a  greater  degree  than  the  two- 
cycle,  and  is  easier  to  keep  adjusted  and  in  good  running  condition. 
Though  the  two-cycle  motor  is  undoubtedly  the  simplest  form,  it  is 
liable  to  be  erratic  in  operation  and  it  is  sometimes  difficult  to  locate 
the  trouble  positively.  They  consume  more  fuel  than  the  four-cycle 
engine  of  the  same  power  and  are  not  so  economical  as  regards  use 
of  lubricating  oil.  Various  types  of  two-cycle  engines  which  have 
been  designed  for  automobile  use  will  be  described  in  a  following 
chapter. 

Power  Plant  Installation.— The  method  of  installing  the  power 
plant  varies  on  different  types  of  automobiles,  though  the  majority  of 
cars  have  the  engine  placed '  at  the  extreme  front  end  of  the  chassis. 
In  some  types  of  cars  where  single  or  double  cylinder  motors  of  the 
horizontal  type  are  used  the  motor  is  placed  under  the  body.  This 
type  of  construction  is  nearly  obsolete  at  this  time,  and  is  found  only 
on  early  forms  of  vehicles  and  one  or  two  commercial  cars. 

The  power  plant  is  sometimes  combined  with  the  clutch  and 
change  speed  gearing  in  such  a  way  as  to  form  a  unit  construction. 
This  method  of  joining  the  parts  is  widely  used  at  the  present  time, 
and  is  superior  to  the  other  common  method  where  the  motor  and 
change  speed  gears  are  independent  units.  Each  method  has  advan- 
tages. As  will  be  seen  by  inspecting  Fig.  51,  A,  when  the  gearset 
and  motor  are  separate  the  transmission  may  be  removed  from  the 
chassis  frame  without  disturbing  the  power  plant  and  vice  versa.  At 
the  other  hand,  when  the  unit  construction,  as  shown  at  B,  is  em- 
ployed, it  is  sometimes  difficult  to  remove  one  member  without  having 
to  take  the  entire  unit  from  the  frame. 

The  unit  construction  has  the  advantage  of  retaining  positive 
alignment  of  the  gearset  with  the  engine  indefinitely.  This  relation 


114 


The  Modern  Gasoline  Automobile 


between  the  parts  is  obtained  when  they  are  first  assembled  and  the 
alignment  cannot  be  changed  by  any  condition  of  operation  after  the 
unit  is  installed  in  the  frame.  This  method  of  mounting  also  per- 
mits the  three-point  suspension  which  is  very  desirable.  For  in- 
stance, the  power  plant  shown  at  A  is  supported  on  four  points  and 
the  gearset  is  supported  on  another  series  of  four  points.  While  the 
tendency  of  these  members  is  to  brace  the  frame  and  prevent  dis- 


B 


Fig.  51.— Defining  Advantages  of  Unit  Power  Plant  Construction  when  Sup- 
ported on  Three  Points. 


alignment,  it  is  possible  on  extremely  rough  roads  for  the  frame 
distortion  to  vary  the  relation  of  the  transmission  and  engine  shaft 
to  some  extent.  Where  a  three-point  suspension  is  employed,  as  out- 
lined at  B,  the  frame  distortion  will  not  impose  stress  on  the  indi- 
vidual members  of  the  power  plant  because  in  a  rigid  unit  construc- 
tion all  parts  must  remain  in  alignment.  The  advantages  of  this 


The  Modern  Gasoline  Automobile 


115 


design  are  becoming  better  appreciated  and  it  is  widely  used  at  the 
present  time. 


Fig.  52. — Four-Cylinder  Power  Plant  and  Transmission  Unit  Adapted  for  Three- 
Point  Support. 

At  Fig.  52,  a  typical  four-cylinder  power  plant  and  transmission 
unit  adapted  for  three-point  support  is  clearly  shown,  while  at  Fig.  53 
a  six-cylinder  unit  power  plant  which  is  designed  for  attachment  .to 
the  frame  at  four  points  is  illustrated.  To  show  the  method  of  power- 


Fig.  53.— Six-Cylinder  Unit  Power  Plant  Utilized  in  Knox  Motor  Car  is  Sup- 
ported by  Four  Points. 


Fig.  54. — Views  of  Typical  Power  Plant  as  Installed  in  Motor-Car  Frame, 

The  Common  Method  of  Installation  in  Pleasure  Cars. 

116 


The  Modern  Gasoline  Automobile  117 

plant  installation  that  is  generally  employed,  the  views  at  Fig.  54  are 
presented,  these  representing  a  typical  four-cylinder  power  plant 
viewed  from  the  front  and  rear,  showing  clearly  the  method  of  sup- 
porting the  engine  base  by  four  arms  and  also  outlining  the  position 
of  the  various  auxiliary  components.  In  some  types  of  commercial 
vehicles  the  motor  is  installed  at  the  front  end  under  the  hood  as 
in  pleasure  car  practice,  but  in  other  cases  it  is  placed  at  practically 
the  same  point  but  under  floor  boards  or  driver's  seat. 

The  advantages  of  the  motor  under  the  seat  location  may  be  very 
well  summed  up  by  saying  that  it  permits  more  loading  space  and 
less  over  all  or  wheel  base  for  a  given  carrying  capacity.  The  shorter 
wheel  base  vehicle  is  especially  valuable  in  congested  city  traffic,  be- 
cause it  may  be  more  easily  controlled  when  driving  in  narrow  thor- 
oughfares, taking  corners,  or  backing  up  to  a  loading  platform.  The 
main  advantage  advanced  for  the  motor  in  front  type  of  commercial 
vehicle  is  accessibility  of  power  plant,  which  may  be  easily  reached 
by  raising  the  hood.  This  feature  is  not  lost  when  the  motor  is  placed 
under  the  seat,  however,  because  all  average  adjustments  may  be  made 
by  raising  the  floor  boards  or  by  opening  a  hinged  door  at  the  side 
of  the  motor  compartment.  Some  makers  who  install  the  motor  under 
the  seat  arrange  the  components  in  such  a  manner  that  they  may 
be  removed  as  units  permitting  ready  access  to  the  motor  and  making 
for  its  prompt  removal  in  event  of  overhauling  or  serious  accident. 
Such  a  construction  is  shown  at  Fig.  55,  which  depicts  a  light  truck 
with  the  seat  and  dash  units  removed  from  the  frame.  It  will  be 
seen  that  the  dash  unit  includes  the  radiator,  control  levers,  fuel  tank 
and  frame,  for  the  support  of  the  floor  boards.  The  seat  unit  is  sep- 
arate and  is  designed  to  fit  over  the  dash  unit  when  it  is  in  place  on 
the  chassis. 


118 


CHAPTEK    III 

The  Principal  Parts  of  Gasoline  Engines — Their  Design,  Construction,  and 
Practical  Application  in  Typical  Power  Plants — Treating  of  the  Cylinders, 
Valve  System  and  Valve  Timing,  Rotary  Valve  Types,  Combination  Piston 
and  Sleeve  Valve  Operation,  Ring  and  Distributor  Valve  Motor  Con- 
struction. 

THE  improvements  noted  in  the  modern  internal  combustion  mo- 
tors have  been  due  to  many  conditions.  The  continual  experimenting 
by  leading  mechanical  minds  could  have  but  one  ultimate  result.  The 
parts  of  the  engines  have  been  lightened  and  strengthened,  and 
greater  power  has  been  obtained  without  increasing  piston  displace- 
ment. A  careful  study  has  been  made  of  the  many  conditions  which 
make  for  efficient  motor  action,  and  that  the  main  principles  are 
well  recognized  by  all  engineers  is  well  shown  by  the  standardization 
of  design  noted  in  modern  power  plants.  There  are  many  different 
methods  of  applying  the  same  principle,  and  it  will  be  the  purpose 
of  this  chapter  to  define  the  ways  in  which  the  construction  may  be 
changed  and  still  achieve  the  same  results.  The  various  components 
may  exist  in  many  different  forms,  and  all  have  their  advantages  and 
disadvantages.  That  all  methods  are  practical  is  best  shown  by  the 
large  number  of  successful  cars  which  use  radically  different  designs. 

Methods  of  Cylinder  Construction. — One  of  the  most  important 
parts  of  the  gasoline  engine  and  one  that  has  material  bearing  upon 
its  efficiency  is  the  cylinder  unit.  Of  late  there  has  been  a  tendency 
to  depart  from  the  previous  methods  of  casting  the  cylinders  individu- 
ally, or  in  pairs,  and  make  all  cylinders  a  unit  or  block  casting.  Some 
typical  methods  of  cylinder  construction  are  shown  at  Fig.  56.  The 
appearance  of  individual  cylinder  castings  of  two  different  types  are 
shown  at  A  and  B.  In  the  former,  the  cylinder  and  cylinder  head 
are  cast  integral  and  the  valves  are  supported  by  inserted  cages.  In 
the  cylinder  design  shown  at  B,  the  head  member  is  a  separate  casting 
from  that  forming  the  cylinder,  and  the  valves  seat  directly  in  this 

119 


Fig.  56. — Illustrating  Differing  Methods  of  Cyl- 
inder Construction  Commonly  Employed.  A — 
Single  or  One-Cylinder  Casting  Used  on  Jack- 
son Cars.  B — Individual  Cylinder  Forming 
Part  of  Knox  Power  Plant.  C — Typical  Twin 
Casting  Generally  Used  on  Motor  Car  Engines. 
D — Four  Cylinders  Cast  in  One  Block,  a  Fea- 
ture of  the  Chalmers  "  30  »  Motor. 


The  Modern  Gasoline  Automobile  121 

member.  It  is  held  to  the  cylinder  by  means  of  four  bolts.  The 
casting  shown  at  C  comprises  two  cylinders  and  is  the  usual  form. 
That  at  D  is  a  block  casting  in  which  the  four  cylinders  are  cast 
together  and  conforms  to  up-to-date  practice. 

Considered  from  a  purely  theoretical  point  of  view  the  individual 
cylinder  casting  has  much  in  its  favor.  It  is  advanced  that  more 
uniform  cooling  is  possible  than-  where  the  cylinders  are  cast  either 
in  pairs  or  three  or  four  in  one  casting.  More  uniform  cooling  in- 
sures that  the  expansion  or  change  of  form  due  to  heating  will  be 
more  equal.  This  is  an  important  condition  because  the  cylinder  bore 
must  remain  true  under  all  conditions  of  operation.  If  the  heating 
effect  is  not  uniform,  which  condition  is  liable  to  obtain  if  metal  is 
not  evenly  distributed,  the  cylinder  may  become  distorted  by  heat 
and  the  bore  be  out  of  truth.  When  separate  cylinders  are  used  it  is 
possible  to  make  a  uniform  water  space  and  have  the  cooling  liquid 
evenly  distributed  around  the  cylinder.  In  multiple  cylinder  castings 
this  is  not  always  the  rule,  as  in  many  instances,  especially  in  four- 
cylinder  block  motors  where  compactness  is  the  main  feature,  there  is 
no  space  between  the  cylinders  for  the  passage  of  water.  Under  such 
circumstances  the  cooling  effect  is  not  even,  and  the  stresses  which 
obtain  because  of  unequal  expansion  may  distort  the  cylinder  to  some 
extent. 

The  advantage  of  casting  the  cylinders  in  blocks  is  that  a  motor 
may  be  much  shorter  than  it  would  be  if  individual  castings  were 
used.  It  is  admitted  that  when  the  cylinders  are  cast  together 
a  more  compact,  rigid,  and  stronger  power  plant  is  obtained  than 
when  cast  separately.  There  is  a  disadvantage,  however,  in  that  if  one 
cylinder  becomes  damaged  it  will  be  necessary  to  replace  the  entire 
unit,  which  means  scrapping  three  good  cylinders  because  one  of  the 
four  has  failed.  When  the  cylinders  are  cast  separately  one  need 
only  replace  that  one  that  has  become  damaged.  The  casting  of  four 
cylinders  in  one  unit  is  made  possible  by  improved  foundry  methods, 
and  when  proper  provision  is  made  for  holding  the  cores  when  the 
metal  is  poured  and  the  cylinder  casts  are  good,  the  construction  is 
one  of  distinct  merit.  It  is  sometimes  the  case  that  the  proportion 
of  sound  castings  is  less  when  cylinders  are  cast  in  block,  but  if  the 
proper  precautions  are  observed  in  molding  and  the  proper  mixtures 


122  The  Modern  Gasoline  Automobile 

of  cast  iron  used,  the  ratio  of  defective  castings  is  no  more  than  when 
cylinders  are  molded  individually.  As  an  example  of  the  courage  of 
modern  motor-car  engineers  in  departing  from  old-established  rules, 
the  cylinder  casting  shown  at  Fig.  57  may  be  considered  typical.  This 
is  a  remarkable  departure  from  standard  construction,  because  not  only 


Fig.  57.— Block  Casting  of  Everitt  "  Six,"  a  Remarkable  Innovation  in  Motor 
Design  Because  Six  Cylinders,  Upper  Part  of  Crank  Case  and  Inlet  and 
Exhaust  Manifolds  are  Included  in  One  Casting. 

the  six  cylinders  are  cast  in  a  block  but  the  upper  part  of  the  engine 
base  and  the  inlet  and  exhaust  manifold  are  also  included  in  the  one 
casting. 

A  method  of  construction  which  is  attracting  some  attention  at 
the  present  time  is  that  shown  at  Fig.  58.  This  is  a  four-cylinder 
motor  in  which  the  four  cylinders  and  the  top  half  of  the  crank  case 
are  cast  together,  but  it  employs  a  separately  cast  head  member  which 
is  common  to  all  cylinders.  This  is  held  to  the  cylinder  casting  by 
means  of  a  series  of  bolts,  and  a  copper-asbestos  gasket,  or  packing, 
is  utilized  in  making  a  gas-  and  water-tight  joint  between  the  parts 
The  advantage  of  this  construction  is  that  it  permits  ready  access  to 
pistons  and  valves  without  dismantling  the  entire  motor  as  is  neces- 


The  Modern  Gasoline  Automobile 


123 


sary  when  the  conventional  form  of  cylinder  casting  is  employed. 
This  type  of  construction  is  also  used  on  some  motors  having  indi- 
vidually cast  cylinders.  The  member  shown  at  Fig.  56,  B,  which 
forms  a  part  of  Knox  power  plant,  has  a  separately  cast  head,  and 
this  construction  is  also  followed  in  the  sleeve  valve  motors  of  the 
Knight  type  previously  described,  and  in  the  Argyle  motor  which  is 
illustrated  at  Fig.  59. 


Fig.  58.— Example  of  Four-Cylinder  Block  Motor  having  One  Separately  Cast 
Head  Member  Common  to  All  Cylinders.  A  Copper-Asbestos  Gasket  is 
Utilized  in  Making  a  Gas-  and  Water-Tight  Joint  Between  the  Parts.  Note 
Accessibility  of  Pistons  and  Valves. 

It  is  common  practice  to  cast  the  water  jackets  integral  with  the 
cylinders,  and  this  is  also  the  most  economical  method  of  applying  it 
because  it  gives  good  results  in  practice.  An  important  detail  is  that 
the  water  spaces  must  be  proportioned  so  that  they  are  equal  around 


124  The  Modern  Gasoline  Automobile 

the  cylinders  whether  these  members  are  cast  individually,  in  pairs, 
threes  or  fours.  When  cylinders  are  cast  in  block  form  it  is  good  prac- 
tice to  leave  a  large  opening  in  the  jacket  wall  which  will  assist  in 
supporting  the  core  and  make  for  uniform  water  space.  It  will  be 
noticed  that  the  casting  shown  at  Fig.  56,  D,  has  a  large  opening  in 
the  side  of  the  cylinder  block.  These  openings  are  closed  after  the 
interior  of  the  casting  is  thoroughly  cleaned  of  all  sand,  core  wire,  etc., 
by  brass,  cast  iron  or  aluminum  plates.  These  also  have  particular 
value  in  that  they  may  be  removed  after  the  motor  has  been  in  use, 
thus  permitting  one  to  clean  out  the  interior  of  the  water  jacket  and 
dispose  of  the  rust,  sediment,  and  incrustation  which  are  always  present 
after  the  engine  has  been  in  active  service  for  a  time. 

Among  the  advantages  claimed  for  the  practice  of  casting  cylinders 
in  blocks  may  be  mentioned  compactness,  lightness,  rigidity,  simplic- 
ity of  water  piping,  as  well  as  permitting  the  use  of  simple  forms  of 
inlet  and  exhaust  manifolds.  The  light  weight  is  not  only  due  to  the 
reduction  of  the  cylinder  mass  but  because  the  block  construction  per- 
mits one  to  lighten  the  entire  motor.  The  fact  that  all  cylinders  are 
cast  together  decreases  vibration,  and  as  the  construction  is  very  rigid, 
disalignment  of  working  'parts  is  practically  eliminated.  When  inlet 
and  exhaust  manifolds  are  cored  in  the  block  casting,  as  is  sometimes 
the  case,  but  one  joint  is  needed  on  each  of  these  instead  of  the  multi- 
plicity of  joints  which  obtain  when  the  cylinders  are  individual  cast- 
ings. The  water  piping  is  also  simplified.  In  the  case  of  a  four- 
cylinder  block  motor  but  two  pipes  are  used;  one  for  the  water  to 
enter  the  cylinder  jacket,  the  other  for  the  cooling  liquid  to  discharge 
through. 

*  Influence  on  Crank-Shaft  Design. — The  method  of  casting  the  cylin- 
ders has  a  material  influence  on  the  design  of  the  crank  shaft  as  will 
be  shown  in  proper  sequence.  When  four  cylinders  are  combined  in 
one  block  it  is  possible  to  use  a  two-bearing  crank  shaft.  Where  cylin- 
ders are  cast  in  pairs  a  three-bearing  crank  shaft  is  commonly  sup- 
plied, and  when  cylinders  are  cast  as  individual  units  it  is  thought 
necessary  to  supply  a  five-bearing  crank  shaft,  though  sometimes 
shafts  having  but  three  journals  are  used  successfully.  Obviously  the 
shafts  must  be  stronger  and  stiffer  to  withstand  the  stresses  imposed 
if  two  supporting  bearings  are  used  than  if  a  larger  number  are  em-' 


Inlet  Pipe 


Detachable' 
Cylinctet  Head 


Exhaust  Pips 


Fig.  59.— Showing  Separate  Head  Construction  of  Argyl  Sleeve  Valve  Motor, 

Made  Necessary  by  Use  of  Sleeve. 

125 


126  The  Modern  Gasoline  Automobile 

ployed.  In  this  connection  it  may  be  stated  that  there  is  less  difficulty 
in  securing  alignment  with  a  lesser  number  of  bearings  and  there  is 
also  less  friction.  At  the  other  hand,  the  greater  the  number  of  points 
of  support  a  crank  shaft  has  the  lighter  the  webs  can  be  made  and  still 
have  requisite  strength. 

,  Combustion  Chamber  Design. — Another  point  of  importance  in  the 
design  of  the  cylinder  and  one  which  has  considerable  influence  upon 
the  power  developed,  is  the  shape  of  the  combustion  chamber.  The 
endeavor  of  designers  is  to  obtain  maximum  power  from  a  cylinder  of 
certain  proportions,  and  the  greater  energy  obtained  without  increas- 
ing piston  displacement  or  fuel  consumption  the  higher  the  efficiency 
of  the  motor.  To  prevent  troubles  due  to  preignition  it  is  necessary 
that  the  combustion  chamber  be  made  so  that  there  will  be  no  rough- 
ness, sharp  corners,  or  edges  of  metal  which  may  remain  incandescent 
when  heated  or  which  will  serve  to  collect  carbon  deposits  by  provid- 
ing point  of  anchorage.  With  the  object  of  providing  an  absolutely 
clean  combustion  chamber  some  makers  use  a  separable  head  unit 
such  as  shown  at  Fig.  56,  B,  and  Figs.  58  and  59.  These  permit  one 
to  machine  the  entire  interior  of  the  cylinder  and  combustion  chamber. 
The  relation  of  valve  location  and  combustion  chamber  design  will  be 
considered  in  proper  sequence. 

-  Bore  and  Stroke  Ratio. — A  question  that  has  been  a  vexed  one  and 
which  has  been  the  subject  of  considerable  controversy  is  the  proper 
proportion  of  the  bore  to  the  stroke.  The  early  gas  engines  had  a 
certain  well-defined  bore  to  stroke  ratio,  as  it  was  usual  at  that  time 
to  make  the  stroke  twice  as  long  as  the  bore  was  wide,  but  this  cannot 
be  done  when  high  speed  is  desired.  With  the  development  of  the 
present-day  motor  the  stroke  or  piston  travel  has  been  gradually  short- 
ened so  that  the  relative  proportions  of  bore  and  stroke  have  become 
nearly  equal.  Of  late  there  seems  to  be  a  tendency  among  designers 
to  return  to  the  proportions  which  formerly  obtained  and  the  stroke 
is  -sometimes  one  and  a  half  or  one  and  three-quarter  times  the  bore. 

Engines  designed  for  high  speed  should  have  the  stroke  not  much 
longer  than  the  diameter  of  the  bore.  The  disadvantage  of  short- 
stroke  engines  is  that  they  will  not  pull  well  at  low  speeds,  though 
tliey  run  with  great  regularity  and  smoothness  at  high  velocity.  The 
long-stroke  engine  is  much  superior  for  slow  speed  work,  and  it  will 


The  Modern  Gasoline  Automobile 


127 


pull  steadily  and  with  increasing  power  at  low  speed.  It  was  formerly 
thought  that  such  engines  should  never  turn  more  than  a  moderate 
number  of  revolutions  in  order  not  to  exceed  the  safe  piston  speed. 


Water  Space 


Combustion     Chamber 


Spark  Plug 
Valve  Gap 


Exhaust 
Manifold 


Flywheel 


Fig.  60.— Section  Through  Sheffield  Simplex  (English)  Engine,  Presented  to 
Show  Excellent  Proportions  of  Water-jacket  Spaces  and  Easy  Gas  Passages 
Leading  to  Valve  Chest. 

While  both  short-  and  long-stroke  motors  have  their  advantages  it 
would  seem  desirable  to  average  between  the  two.  That  is  wjiy 
a  proportion  of  four  to  five  or  six  seems  to  be  more  general  than  that 


128 


The  Modern  Gasoline  Automobile 


of  four  to  seven  or  eight,  which  would  be  a  long-stroke  ratio.    At  Fig. 
61  a  section  through  the  cylinder  of  a  Sizaire-Naudin  motor  is  shown. 


Fig.  61.— Section  Through  Sizaire-Naudin  (French)  Motor,  Showing  a  Typical 
Small-Bore,  Long-Stroke  Cylinder. 


This  illustrates  a  typical  small-bore,,  long-stroke  design  which  has 
worked  very  well  even  at  high  speeds.  That  at  Fig.  62  is  also  a  long- 
stroke  type. 


The  Modern  Gasoline  Automobile 


129 


Value 


Piston 


Connecting  Rod 


Meaning  of  Piston  Speed. — The  factor  which  limits  the  stroke  and 
makes  the  speed  of  rotation  so  dependent  upon  the  travel  of  the  piston 
is  piston  speed.  Heretofore,  it  has  been  considered  desirable  not  to 
exceed  a  speed  of  one  thousand  feet  per  minute.,  which  has  been  de- 
iermined  to  make  for 
greatest  efficiency,  com- 
bined with  endurance, 
by  many  authorities  on 
design  and  construction 
of  internal  combustion 
motors.  During  the  past 
few  years  there  have 
been  instances  where  en- 
gines were  giving  satis- 
factory service  with  pis- 
ton speed  of  1,200  to 
1,500  feet  per  minute. 
Lubrication  is  the  main 
factor  which  determines 
piston  speed,  and  the 
higher  the  rate  of  piston 
travel  the  greater  care 
must  be  taken  to  insure 
proper  oiling.  Let  us 
fully  consider  what  is 
meant  by  piston  speed. 

Assume  that  a  motor 
has  a  piston  travel  or 
stroke  of  six  inches, 
for  the  sake  of  illustra- 
tion. It  would  take  two 
strokes  of  the  piston  to 
cover  one  foot,  or  twelve 
inches,  and  as  there  are 
two  strokes  to  a  revo- 


Fig.  62.— End  View  Humber  (English)  Motor, 
Depicting  Off-set  Cylinder  Construction. 


lution  it  will  be  seen  that  this  permits  of  a  normal  speed  of  1,000 
revolutions  per  minute  for  an  engine  with  a  six-inch  stroke.     If  the 


130  The  Modern  Gasoline  Automobile 

stroke  was  only  four  inches,  a  normal  speed  of  1,500  revolutions  per 
minute  would  be  possible  without  exceeding  the  prescribed  limit.  The 
crank  shaft  of  a  small  engine,  having  three-inch  stroke,  could  turn  at 
a  speed  of  2,000  revolutions  per  minute  without  danger  of  exceeding 
the  safe  speed  limit.  It  will  be  seen  that  the  longer  the  stroke  the 
slower  the  speed  of  the  engine,  if  one  desires  to  keep  the  piston  speed 
within  the  bounds  as  recommended. 

Advantages  of  Off-Set  Cylinders. — Another  point  upon  which  con- 
siderable difference  of  opinion  exists  relates  to  the  method  of  placing 
the  cylinder  upon  the  crank  case — i.  e.,  whether  its  center  line  should  be 
placed  directly  over  the  center  of  the  crank  shaft,  or  to  one  side  of 
center.  The  motor  shown  at  Fig.  62  is  an  off-set  type,  in  that  the  cen- 
ter line  of  the  cylinder  is  a  little  to  one  side  of  the  center  of  the 
crank  shaft.  Diagrams  are  presented  at  Fig.  63  which  show  the  ad- 
vantages of  off-set  crank-shaft  construction.  The  view  at  A  is  a  sec- 
tion through  a  simple  motor  with  the  conventional  cylinder  placing, 
the  center  line  of  both  crank  shaft  and  cylinder  coinciding.  The  view 
at  B  shows  the  cylinder  placed  to  one  side  of  center  so  that  its  center 
line  is  distinct  from  that  of  the  crank  shaft  and  at  some  distance  from 
it.  The  amount  of  offset  allowed  is  a  point  of  contention,  the  usual 
amount  being  from  fifteen  to  twenty-five  per  cent  of  the  stroke.  The 
advantages  of  the  offset  are  shown  at  Fig.  63,  C.  If  the  crank  turns 
in  direction  of  the  arrow  there  is  a  certain  resistance  to  motion  which 
is  proportional  to  the  amount  of  energy  exerted  by  the  engine  and  the 
resistance  offered  by  the  load.  There  are  two  thrusts  acting  against 
the  cylinder  wall  to  be  considered,  that  due  to  explosion  or  expansion 
of  the  gas  and  that  which  resists  the  motion  of  the  piston.  These 
thrusts  may  be  represented  by  arrows,  one  which  acts  directly  in  a 
vertical  direction  on  the  piston  top,  the  other  along  a  straight  line 
through  the  center  of  the  connecting  rod.  Between  these  two  thrusts 
one  can  draw  a  line  representing  a  resultant  force  which  serves  to 
bring  the  piston  in  forcible  contact  with  one  side  of  the  cylinder  wall, 
this  being  known  as  side  thrust.  As  shown  at  C,  the  crank  shaft  is  at 
90  degrees  or  about  one-half  stroke  and  the  connecting  rod  is  at  20  de- 
grees angle.  The  shorter  connecting  rod  would  increase  the  diagona 
resultant  and  side  thrusts  while  a  longer  one  would  reduce  the  angl 
and  the  connecting  rod  and  the  side  thrust  of  the  piston  would 


The  Modern  Gasoline  Automobile 


131 


less.  With  the  off-set  construction,  as  shown  at  D,  it  will  be  noticed 
that  with  the  same  connecting  rod  length  as' shown  at  C  and  with  the 
crank  shaft  at  90  degrees  of  the  circle  that  the  connecting  rod  angle  is 
14  degrees  and  the  side  thrust  is  reduced  proportionately. 


nun 


mj 


Thrust  Due  to  Explosion 


of  Side 

Thrust  Against 
Cylinder  Wall, 
Which  Increase 
With  Angularity 
of  Connecting 
Rod          , 


I     Resistance  to  / 

Motion    Center  Line  of 
Crunk 


Note  Decreased 
Side  Thrust 
Because  of  Lesser 

Angle  of 
Connecting  Rod 


Center  Line  of 
Cylinder 


Fig.   63. — Diagrams  Demonstrating  Advantages  of  Off-set  Crank-Shaft   Con- 
struction. 

Another  important  advantage  is  that  greater  efficiency  is  obtained 
from  the  explosion  with  an  off-set  crank  shaft,  because  the  crank  is 
already  inclined  when  the  piston  is  at  top  center  and  all  the  energy 
imparted  to  the  piston  by  the  burning  mixture  can  be  exerted  .directly 
into  producing  a  useful  turning  effort.  When  a  cylinder  is  placed  di- 
rectly on  a  line  with  the  crank  shaft,  as  shown  at  A,  it  will  be  evident 
that  some  of  the  force  produced  by  the  expansion  of  the  gas  will  be 


132 


Tlie  Modern  Gasoline  Automobile 


133 


exerted  in  a  direct  line  and  until  the  crank  moves  the  crank  throw 
and  connecting  rod  are  practically  a  solid  member.  The  pressure 
which  might  be  employed  in  obtaining  useful  turning  effort  is  wasted 
by  causing  a  direct  pressure  upon  the  lower  half  of  the  main  bearing 
and  the  upper  half  of  the  crank-pin  bushing. 

Very  good  and  easily  understood  illustrations  showing  advantages 
of  the  off-set  construction  are  shown  at  E  and  F.     This  is  a  bicycle 


Inlet  Value 
Exhaust  Valve 


Center  Bearing 


Fig.   65.— Section   Through  Typical  Four-Cylinder  Block   Motor  with   Three- 
Bearing  Crank  Shaft. 

crank  hanger.  It  is  advanced  that  the  effort  of  the  rider  is  not  as  well 
applied  when  the  crank  is  at  position  E  as  when  it  is  at  position  F. 
Position  E  corresponds  to  the  position  of  the  parts  when  the  cylinder 
is  placed  directly  over  the  crank-shaft  center.  Position  F  may  be 
compared  to  the  condition  which  is  present  when  the  off-set  cylinder 
construction  is  used. 

Influence  of  Cylinder  Construction  on  Engine  Design. — To  show  the 
manner  in  which  the  various  methods  of  casting  cylinders  previously 


134 


The  Modern  Gasoline  Au-tomobile 


135 


defined  may  alter  engine  design  some  views  of  typical  power  plants  are 
presented.  That  at  Fig.  64  is  a  part  sectional  view  of  the  Sheffield 
Simplex,  an  English  six-cylinder  motor.  In  this  the  cylinders  are 
cast  in  blocks  of  three,,  and  the  motor  is  composed  of  two  blocks.  A 
seven-bearing  crank  shaft  is  used,  there  being  a  journal  between  each 
pair  of  cylinders  in  addition  to  the  two  end  members.  A  feature  of 
this  power  plant  that  may  be  commended  is  the  exceptionally  good 
water  jacketing  of  the  cylinders.  The  water  spaces  are  large  and  all 
parts  of  the  cylinder  are  surrounded  by  cooling  liquid. 


Water  Pipe 


Breather  Pipe 


Individual  Cylinder 


ther  Pipe 


Main  Bearing 


Rear  Bearing 


Fig.  67. — Sectional  View  of  Typical  Four-Cylinder  Motor  Using  Individual  Cylin- 
der Castings  with  Cylinder  Heads  Cast  Integral.  General  Design  Fair, 
Excepting  that  of  Connecting  Rods. 

At  Fig.  65  a  section  through  a  typical  four-cylinder  block  motor 
is  given.  In  this  power  plant  a  short  crank  case  is  used,  but  the  crank 
shaft  is  supported  on  three  bearings  instead  of  two  journals  as  is  com- 
mon practice  with  four-cylinder  motors.  To  show  the  use  of  indi- 


136  Tlie  Modern  Gasoline  Automobile 

vidual  castings  the  motors  shown  at  Figs.  66  and  67  are  valuable.  It 
will  be  evident  if  these  are  compared  to  Fig.  65  that  the  motor  will 
have  a  greater  overall  length  than  when  all  cylinders  are  cast  in 
one  block.  In  the  motor  shown  at  Fig  66  a  five-bearing  crank  shaft 
is  employed  while  that  at  Fig.  67  uses  a  three-bearing  crank  shaft. 
There  are  a  number  of  other  constructional  details  dependent  upon 
cylinder  design  which  merit  detailed  description  such  as  valve  placing 
and  operation,  crank  case  design,  etc.,  but  these  are  of  sufficient  im- 
portance to  be  discussed  in  a  more  comprehensive  manner  and  will  be 
considered  separately. 

Valve  Location  of  Vital  Import. — It  has  often  been  said  that  a  chain 
is  no  stronger  than  its  weakest  link  and  this  is  as  true  of  the  explosive 
motor  as  it  is  of  any  other  piece  of  mechanism.  Many  motors  which 
appeared  to  be  excellently  designed  and  which  were  well  constructed 
did  not  prove  satisfactory,  because  some  minor  detail  or  part  had  not 
been  properly  considered  by  the .  designer.  A  factor  having  material 
bearing  upon  the  efficiency  of  the  internal  combustion  motor  is  the 
location  of  the  valves  and  the  shape  of  the  combustion  chamber  which 
is  largely  influenced  by  their  placing.  The  fundamental  consideration 
of  valve  design  is  that  the  gases  be  admitted  and  discharged  from  the 
cylinder  as  quickly  as  possible  in  order  that  the  speed  of  gas  flow  will 
not  be  impeded  and  produce  back  pressure.  This  is  imperative  in  ob- 
taining satisfactory  operation  in  any  form  of  motor.  If  the  inlet 
passages  are  constricted  the  cylinder  will  not  fill  with  explosive  mix- 
ture promptly,  whereas  if  the  exhaust  gases  are  not  fully  expelled  the 
parts  of  the  inert  products  of  combustion  retained  dilute  the  fresh 
charge,  making  it  slow  burning  and  causing  lost  power  and  overheat- 
ing. When  an  engine  employs  water  as  a  cooling  medium  this  sub- 
stance will  absorb  the  surplus  heat  readily,  and  the  effects  of  over- 
heating are  not  noticed  as  quickly  as  when  air-cooled  cylinders  are 
employed.  Valve  sizes  have  a  decided  bearing  upon  the  speed  of  mo- 
tors and  some  valve  locations  permit  the  use  of  larger  members  than  do 
other  positions. 

While  piston  velocity  is  an  important  factor  in  determinations  of 
power  output  it  must  be  considered  from  the  aspect  of  the  wear  pro- 
duced upon  the  various  parts  of  the  motor.  It  is  evident  that  engines 
which  run  very  fast,  especially  of  high  power,  must  be  under  a  greater 


The  Modern  Gasoline  Automobile  137 

strain  than  those  operating  at  lower  speeds.  The  valve-operating 
mechanism  is  especially  susceptible  to  the  influence  of  rapid  move- 
ment, and  the  slower  the  engine  the  longer  the  parts  will  wear  and  the 
more  reliable  the  valve  action. 

As  will  be  seen  by  reference  to  the  accompanying  illustrations, 
there  are  many  ways  in  which  valves  may  be  placed  in  the  cylinder. 
Each  method  outlined  possesses  some  point  of  advantage  because 
all  of  the  types  illustrated  are  used  by  reputable  automobile  manu- 
facturers. The  method  outlined  at  Fig.  68,  A,  is  widely  used  and 
because  of  its  shape  the  cylinder  is  known  as  the  "  T  "  form.  It 
is  approved  for  several  reasons,  the  most  important  being  that  large 
valves  can  be  employed  and  a  well-balanced  and  symmetrical  cylinder 
casting  obtained.  Two  independent  cam  shafts  are  needed,  one  op- 
erating the  inlet  valves,  the  other  the  exhaust  members.  The  valve- 
operating  meclianism  can  be  very  simple  in  form,  consisting  of  a 
plunger  actuated  by  the  cam  which  transmits  the  cam  motion  to  the 
valve  stem,  raising  the  valve  as  the  cam  follower  rides  on  the  point  of 
the  cam.  Piping  may  be  placed  without  crowding,  and  larger  mani- 
folds can  be  fitted  than  in  some  other  constructions.  This  has  special 
value,  as  it  permits  the  use  of  an  adequate  discharge  pipe  on  the  ex- 
haust side  with  its  obvious  advantages. 

At  the  other  hand,  if  considered  from  a  viewpoint  of  actual  heat 
efficiency,  it  is  theoretically  the  worst  form  of  combustion  chamber. 
This  disadvantage  is  probably  compensated  for  by  uniformity  of  ex- 
pansion of  the  cylinder  because  of  balanced  design.  The  ignition 
spark  plug  may  be  located  directly  over  the  inlet  valve  in  the  path  of 
the  incoming  fresh  gases,  and  both  valves  may  be  easily  removed  and 
inspected  by  unscrewing  the  valve  caps  without  taking  off  the  mani- 
folds. 

The  valve  installation  shown  at  D  is  somewhat  unusual,  though  it 
provides  for  the  use  of  valves  of  large  diameter.  Easy  charging  is 
insured  because  of  the  large  inlet  valve  directly  in  the  top  of  the  cyl-. 
inder.  Conditions  may  be  reversed  if  necessary,  and  the  gases  dis- 
charged through  this  large  valve.  Both  methods  are  used,  though  it 
would  seem  that  the  free  exhaust  provided  by  allowing  the  gases  to 
escape  directly  from  the  combustion  chamber  through  the  overhead 
valve  to  the  exhaust  manifold  would  make  for  more  power.  The 


138 


The  Modern  Gasoline  Automobile 


139 


incoming  fresh  gas  cannot  fail  to  flow  into  the  cylinder  easily,  because 
it  is  drawn  into  the  cylinder  by  the  pumping  action  of  the  piston, 
whereas  if  the  inert  gas  is  not  expelled  promptly  the  factor  of  back 


Rocker  Arm 


Rocker  Arm 


Valve  Cage 


Fig.  69.— Benz  Racing  Motor,  Presented  to  Show  Method  of  Valve  Placing  so 
these  Members  Open  Directly  into  the  Cylinder  Head. 


140  The  Modern  Gasoline  Automobile 

pressure  is  of  some  importance.  The  method  outlined  at  Fig.  69  is 
one  that  has  been  widely  employed  on  large  racing  motors  where  ex- 
treme power  as  required  as  well  as  in  engines  constructed  for  regular 
service.  The  inclination  of  the  valve  cages  permits  the  use  of  large 
valves  and  these  open  directly  into  the  combustion  chamber.  There 
are  no  pockets  to  retain  heat  or  dead  gas,  and  free  intake  and  outlet  of 
gas  is  obtained.  This  form  is  quite  satisfactory  from  a  theoretical 
point  of  view  because  of  the  almost  ideal  combustion  chamber  form. 
Some  difficulty  is  experienced,  however,  in  properly  water- jacketing 
the  valve  chamber  which  experience  has  shown  to  be  necessary  if  the 
engine  is  to  have  high  power. 

The  motor  shown  at  Fig.  62  employs  a  cylinder  of  the  "  L  "  type. 
Both  valves  are  placed  in  a  common  extension  from  the  combustion 
chamber,  and  being  located  side  by  side  both  are  actuated  from  a  com- 
mon cam  shaft.  The  inlet  and  exhaust  pipes  are  placed  on  the  same 
side  of  the  engine  and  a  very  compact  assemblage  is  obtained.  The 
valves  may  be  easily  removed  if  desired,  and  the  construction  is  fairly 
good  from  the  viewpoint  of  both  foundry  man  and  machinist.  The 
chief  disadvantage  is  the  limited  area  of  the  valves  and  the  loss  of 
heat  efficiency  due  to  the  'pocket.  This  form  of  combustion  chamber, 
however,  is  more  efficient  than  the  "  T  "  head  construction,  though 
with  the  latter  the  use  of  larger  valves  probably  compensates  for  the 
greater  heat  loss.  It  has  been  stated  as  an  advantage  of  this  construc- 
tion that  both  manifolds  can  be  placed  at  the  same  side  of  the  engine 
and  a  compact  assembly  secured.  At  the  other  hand,  the  disadvantage 
may  be  cited  that  in  order  to  put  both  pipes  on  the  same  side  they 
must  be  of  smaller  size  than  can  be  used  when  the  valves  are  oppo- 
sitely placed.  The  "  L  "  form  cylinder  may  be  made  more  efficient  if 
but  one  valve  is, placed  in  the  pocket  while  the  other  is  placed  in  the 
cylinder  head.  This  construction  is  well  shown  at  Fig.  70,  which  is 
a  side  sectional  view  of  the  same  motor  depicted  in  end  section  at  Fig. 
68,  B.  The  large  valves  one  can  use  are  well  emphasized  in  this  illus- 
tration. 

The  method  of  valve  application  shown  at  Fig.  71  is  an  ingenious 
method  of  overcoming  some  of  the  disadvantages  inherent  with  valve- 
in-the-head  motors.  In  the  first  place  it  is  possible  to  water-jacket  the 
valves  thoroughly,  which  is  difficult  to  accomplish  when  they  are 


The  Modern  Gasoline  Automobile 


141 


mounted  in  cages.  The  water  circulates  directly  around  the  walls  of 
the  valve  chambers  which  is  superior  to  a.  construction  where  separate 
cages  are  used,  as  there  are  two  thicknesses  of  metal  with  the  latter, 


Rocher  Arm 


Tappet  Rod 


Exhaust 
Valve 


Fig.  70.— Part  Sectional  View  of  Bergdoll  Motor,  Showing  Placing  of  Valves. 
The  Exhaust  Member  is  Fitted  in  a  Side  Pocket  of  the  L  Cylinder.  The 
Inlet  Valve  is  Placed  Directly  in  the  Center  of  the  Combustion  Chamber. 

that  of  the  valve  cage  proper  and  the  wall  of  the  cylinder.  The  cool- 
ing medium  is  in  contact  only  with  the  outer  wall,  and  as  there  is 
always  a  loss  of  heat  conductivity  at  a  joint  it  is  practically  impossi- 
ble to  keep  the  exhaust  valves  and  their  seats  at  a  uniform  temper- 


142  The  Modern  Gasoline  Automobile 

ature.  The  valves  may  be  of  larger  size  without  the  use  of  pockets 
when  seating  directly  in  the  head.  In  fact,  they  could  be  equal  in 
diameter  to  almost  half  the  bore  of  the  cylinder,  which  provides  an 
ideal  condition  of  charge  placement  and  exhaust. 


ROCKffi 
ARM 


VALVE 


Fig.  71. — Cylinder  Head  of  Knox  Engine  Cut  in  Two  to  Show  Method  of  Valve 
Placing  and  Seating  Directly  in  Separately  Cast  Member.  Valves  Operated 
by  Rocker  Arms.  Note  Exceptionally  Good  Water  Spaces  Around  Valve 
Seats. 

When  valve  grinding  is  necessary  the  entire  head  is  easily  removed 
by  taking  off  four  nuts  and  loosening  inlet  and  exhaust  manifold  con- 
nections, which  operation  would  be  necessary  even  if  cages  were 
employed.  The  cylinder  is  easily  cast  and  machined,  and  as  the  head 
is  separately  water- jacketed  there  is  no  water  joint  between  the  head 
and  cylinder  which  must  be  made  tight  with  a  packing  capable  of 
resisting  both  water  and  hot  gas.  The  sole  function  of  the  copper 
asbestos  washer  which  fits  in  the  annular  groove  in  the  cylinder  head 
is  to  prevent  escape  of  gas.  The  ease  with*  which  the  head  and  cylin- 
der may  be  machined  and  smooth  combustion  chamber  obtained  has 
been  previously  dealt  with. 


The  Modern  Gasoline  Automobile 


143 


The  form  shown  at  Fig.  72  shows  an  ingenious  application  of  the 
valve-in-the-head  idea  which  permits  one  to  obtain  large  valves.  It 
has  been  used  on  some  of  the  Franklin  air-cooled  cars.  The  inlet  pas- 
sage is  controlled  by  the  sliding  sleeve  which  is  hollow  and  slotted  so 
as  to  permit  the  exhaust  gases  to  leave  the  cylinder  and  out  through 
the  regular  type  poppet  valve  which  seats  in  the  inlet  sleeve.  When 


EXHAUST 
TAPPET, 


EXHAUST 
SPRING 


Fig.  72. — Section  Through  Concentric  Valve  Used  on  Some  Franklin  Models. 
The  Exhaust  Valve,  which  is  a  Regular  Poppet  Type,  Seats  in  the  Inlet  Mem- 
ber, which  is  a  Hollow  Shell  of  Metal.  Both  Valves  Open  Directly  into 
the  Combustion  Chamber. 

the  inlet  sleeve  is  operated  by  the  tappet  rod  and  rocker  arm  the  ex- 
haust valve  is  also  carried  down  with  it.  The  exhaust  gas  passage  is 
closed,  however,  and  the  fresh  gases  are  taken  in  through  the  large 
annular  passage  surrounding  the  inlet  sleeve.  When  the  inlet  valve 


144 


The  Modern  Gasoline  Automobile 


Value  Cap 
Value  Pocket 


Fig.  73. — Section  Through  Cylinder  of  Hudson  Car.  A  Typical  Form  Having 
L-shaped  Cylinder  with  Inlet  and  Exhaust  Valves  on  Same  Side  of  Cylinder 
and  Actuated  from  Common  Cam  Shaft.  Note  Plate  Used  to  Enclose 
Valve  Springs. 


The  Modern  Gasoline  Automobile  145 

leaves  its  seat  in  the  cylinder  the  passage  of  cool  gas  around  the  sleeve 
keeps  the  temperature  of  both  valves  to  a  low  point  and  the  danger  of 
warping  is  minimized.  A  dome-shaped  combustion  chamber  may  be 
used  which  is  an  ideal  form  in  conserving  heat  efficiency  and  as  large 
valves  may  be  installed  the  flow  of  both  fresh  and  exhaust  gases  may 
be  obtained  with  minimum  resistance. 

At  Fig.  73  a  section  through  a  typical  "L  "-shaped  cylinder  is 
depicted.  It  will  be  evident  that  where  a  pocket  construction  is  em- 
ployed in  addition  to  its  faculty  for  absorbing  heat,  the  passage  of 
gas  would  be  impeded.  For  example,  the  inlet  gas  rushing  in  through 
the  open  valve  would  impinge  sharply  upon  the  valve  cap  directly 
over  the  valve  and  then  must  turn  at  a  sharp  angle  to  enter  the  com- 
bustion chamber  and  then  at  another  sharp  angle  to  fill  the  cylinders. 
The  same  conditions  apply  to  the  exhaust  gases,  though  they  are  re- 
versed. When  the  valve-in-the-head  type  of  cylinder  is  employed  the 
only  resistance  offered  the  gas  is  in  the  manifold.  As  far  as  the  pas- 
sage of  the  gases  in  and  out  of  the  cylinder  is  concerned  ideal  condi- 
tions obtain.  It  is  claimed  that  valve-in-the-head  motors  are  more 
flexible  and  responsive  than  other  forms  but  the  construction  has  the 
disadvantage  in  that  the  valves  must  be  opened  through  a  rather 
complicated  system  of  push  rods  and  rocker  arms  instead  of  the  sim- 
pler and  direct  plunger  which  can  be  used  with  either  the  "  T  "  or 
"  L  "  head  cylinders. 

Valve  Design  and  Construction. — Valve  dimensions  are  an  im- 
portant detail  to  be  considered  and  can  be  determined  by  several  con- 
ditions, among  which  may  be  cited  method  of  installation,  operating 
mechanism,  material  employed,  engine  speed  desired,  manner  of  cyl- 
inder cooling,  and  degree  of  lift  desired.  A  review  of  various  methods 
of  valve  location  has  shown  that  when  the  valves  are  placed  directly  in 
the  head,  we  can  obtain  the  ideal  cylinder  form  though  larger  valves 
may  be  used  if  housed  in  a  separate  pocket,  as  afforded  by  the  "  T  '*' 
head  construction.  The  method  of  operation  has  much  to  do  with 
the  size  of  the  valves.  For  example,  if  an  automatic  inlet  valve  is 
employed  it  is  good  practice  to  limit  the  lift  and  obtain  the  required 
area  of  port  opening  by  augmenting  the  diameter.  Because  of  this  a 
valve  of  the  automatic  type  is  usually  made  twenty  per  cent  larger 
than  one  mechanically  operated.  When  both  are  actuated  by  cam 


146 


The  Modern  Gasoline  Automobile 


mechanism,  as  is  now  common  practice,  they  are  usually  made  the 
same  size  and  are  interchangeable,  which  greatly  simplifies  manufac- 
ture. The  relation  of  valve  diameter  to  cylinder  bore  is  one  that  has 
been  discussed  for  some  time  by  engineers.  The  writer's  experience 
would  indicate  that  they  should  be. at  least  half  the  bore,  if  possible. 
The  larger  the  area  of  the  valve  the  less  lift  required,  and  this  is  an 
important  factor  where  high  rotative  speeds  are  desired.  A  valve  with 
a  small  lift  will  reach  its  maximum  opening  sooner  and  close  quicker 
than  one  with  a  high  lift  and  small  diameter.  This  will  produce  less 
wear  on  the  parts  and  tend  to  more  silent  operation. 

At  the  other  hand,  a  large  diameter  valve  is  more  apt  to  warp  than 
a  narrower  one,  and  greater  care  is  needed  in  securing  positive  cooling 


Cast  Iron  Head 


Flat  Siat 


Key  Slot 


A 


Fig.  74. — Type  of  Valves  in  Common  Use.  A — One-Piece  Steel  Valve  of  Good 
Design  which  Permits  Easy  Gas  Flow.  B — Steel  Valve  Made  by  Electric- 
ally Welding  a  Nickel  Steel  Head  to  a  Carbon  Steel  Stem.  C— A  Con- 
struction Often  Employed  for  Exhaust  Valves,  a  Two-Piece  Built-Up  Mem- 
ber. D— Valve  with  Flat  Seat,  Often  Used  to  Admit  Mixture  to  Cylinder. 

when  large  diameter  members  are  used.  While  the  mushroom  type  or 
poppet  valve  has  become  standard  and  is  the  most  widely  used  form  at 
the -present  time,  there  is  some  difference  of  opinion  among  designers 
as  to  the  materials  employed  and  the  angle  of  the  seat.  Most  valves 
have  a  bevel  seat,  though  some  have  a  flat  seating,  as  shown  at  Kig. 
74,  D.  The  flat  seat  valve  has  the  distinctive  advantage  of  providing  a 
clear  opening  with  lesser  lift,  this  conducing  to  free  gas  flow.  It  also 


The  Modern  Gasoline  Automobile  147 

has  value  because  it  is  silent  in  operation,  but  the  disadvantage  is  pres- 
ent that  best  material  and  workmanship  must  be  used  in  their  con- 
struction to  obtain  satisfactory  results.  As  it  can  be  made  very  light 
it  is  particularly  well  adapted  for  use  as  an  automatic  inlet  valve. 
Among  other  disadvantages  cited  is  the  claim  that  it  is  more  sus- 
ceptible to  derangement  owing  to  the  particles  of  foreign  matter  get- 
ting under  the  seat.  With  a  bevel  seat  valve  it  is  argued  that  the 
foreign  matter  would  be  more  easily  dislodged  by  the  gas  flow,  and 
that  the  valve  would  close  tighter  because  it  is  drawn  positively  against 
the  bevel  seat. 

Several  methods  of  valve  construction  are  the  vogue,  the  most 
popular  form  being  the  one-piece  type;  though  those  which  are  com- 
pose;! of  a  head  of  one  material  and  stem  of  another  are  often  used. 
If  the  built-up  construction  is  favored  the  head  is  usually  of  high 
nickel  steel,  Monel  metal,  or  cast  iron,  which  metals  possess  good  heat 
resisting  qualities.  Heads  made  of  these  materials  are  not  likely  to 
warp,  scale,  or  pit,  as  is  sometimes  the  case  when  ordinary  grades  of 
machinery  steel  are  used.  The  cast-iron  head  construction  is  not 
popular  because  it  is  often  difficult  to  keep  the  head  tight  on  the  stem. 
There  is  a  slight  difference  in  expansion  ratio  between  the  head  and 
the  stem,  and  as  the  stem  is  either  screwed  or  riveted  to  the  cast-iron 
head  the  constant  hammering  of  the  valve  against  its  seat  may  loosen 
the  joint.  As  soon  as  the  head  is  loose  on  the  stem  the  action  of  the 
valve  becomes  erratic. 

The  valve  shown  at  Fig.  74,  A,  is  made  from  a  forging  of  thirty-five 
per-cent  nickel  steel  in  the  large  sizes,  and  is  often  machined  from  the 
bar  by  automatic  machinery  in  making  the  smaller  sizes.  Among  the 
factors  considered  in  design  are  to  make  the  stems  of  ample  size  so  that 
they  will  not  be  likely  to  bend,  and  to  leave  enough  metal  between  the 
stem  and  the  head  so  that  the  gases  may  be  directed  toward  the  periph- 
ery of  the  head.  This  has  a  tendency  to  make  a  slightly  heavier  valve 
than  that  shown  at  Fig.  74,  B.  It  is  also  considered  good  practice  to 
use  a  domed  or  arched  head  instead  of  one  that  is  perfectly  flat,  and  it 
is  advisable  to  leave  the  head  smooth  and  without  a  slotted  boss  which 
is  often  left  on  so  that  a  screw-driver  blade  can  be  used  to  turn  the 
valve  when  grinding  it.  When  the  arched  head  construction  is  used 
two  small  holes  may  be  drilled  into  it.  These  have  the  advantage  of 


148  The  Modern  Gasoline  Automobile 

leaving  no  sharp  edges  exposed  to  retain  heat  and  cause  too  early  ex- 
plosions of  gas.  If  desired,  a  slot  may  be  cut  directly  in  the  head  and 
the  valve  turned  with  a  screw-driver. 

The  form  of  valve  shown  at  B  is  a  common  one,  and  its  only 
advantage  is  that  the  design  permits  of  light  construction.  The 
slotted  boss  is  not  desirable  for  the  reason  previously  outlined,  the 
valve  head  is  not  as  strong  as  that  shown  at  A  and  it  will  warp  sooner. 
The  point  of  weakness  where  the  stem  joins  the  head  may  cause 
trouble.  As  the  gases  strike  the  under  surface  and  are  sharply  de- 
flected at  a  sharp  angle  instead  of  having  an  easy  flow  the  passage  is 
somewhat  impeded.  The  form  of  construction  is  a  nickel  steel  head 
electrically  welded  to  a  machinery  steel  stem.  The  former  material 
is  a  better  heat-resisting  substance  while  the  softer  steel  makes  a  bet- 
ter bearing.  The  joint  is  indistinguishable  because  the  metals  are' 
fused  together,  and  that  point  is  as  strong  as  any  other  part  of  the 
stem.  The  valve  shown  at  C  is  composed  of  a  cast-iron  head  member 
screwed  on  to  a  steel  stem.  The  construction  at  D  is  a  good  example 
of  flat  seat  inlet  valve. 


Fig.  75. — Forms  of  Valve-Lifting  Cams  Generally  Employed.  A — Cam  Profile 
for  Long  Dwell  and  Quick  Lift.  B — Typical  Inlet  Cam  Used  with  Mush- 
room Type  Follower.  C — Average  Form  of  Cam.  D — Designed  to  Give 
Quick  Lift  and  Gradual  Closing. 

Valve  Operation. — The  methods  of  valve  operation  commonly  used 
vary  according  to  the  type  of  cylinder  construction  employed.  In  all 
cases  the  valves  are  lifted  from  their  seats  by  cam  actuated  mechan- 
ism. Various  forms  of  valve-lifting  cams  are  shown  at  Fig.  75.  As 
will  be  seen,  a  cam  consists  of  a  circle  to  which  a  raised,  approximately 
triangular  member  has  been  added  at  one  point.  When  the  cam  fol- 


The  Modern  Gasoline  Automobile 


149 


lower  rides  on  the  circle,  as  shown  at  Fig.  76,  there  is  no  difference  in 
height  between  the  cam  center  and  its  periphery  and  there  is  no  move- 
ment of  the  plunger.  As  soon  as  the  raised  portion  of  the  cam  strikes 
the  plunger  it  will  lift  it,  and  this  reciprocating  movement  is  trans- 
mitted to  the  valve  stem  by  suitable  mechanical  connections. 

The  cam  forms  outlined  at  Fig.  75  are  those  commonly  used.  That 
at  A  is  used  on  engines  where  it  is  desired  to  obtain  a  quick  lift  and 
to  keep  the  valve  fully  opened  as  long  as  possible.  It  is  a  noisy  form, 
however,  and  is  not  very  widely  employed.  That  at  B  is  utilized  more 
often  as  an  inlet  cam  while  the  profile  shown  at  C  is  generally  de- 
pended on  to  operate  exhaust  valves.  The  cam  shown  at  D  is  a  com- 
posite form  which  has  some  of  the  features  of  the  other  three  types. 
It  will  give  the  quick  opening  of  form  A,  the  gradual  closing  of  form 
B,  and  the  time  of  maximum  valve  opening  provided  by  cam  profile  C. 


•Plunger 


Fig.  76. — Showing  Principal  Types  of  Cam  Followers  which  Have  Received 

General  Application. 

The  various  types  of  valve  plungers  used  are  shown  at  Fig^  76. 
That  shown  at  A  is  the  simplest  form,  consisting  of  a  simple  cylindri- 
cal member  having  a  rounded  end  which  follows  the  cam  profile. 
These  are  sometimes  made  of  square  stock  or  kept  from  rotating  by 


150  The  Modern  Gasoline  Automobile 

means  of  a  key  or  pin.  A  line  contact  is  possible  when  the  plunger  is 
kept  from  turning  whereas  but  a  single  point  bearing  is  obtained 
when  the  plunger  is  cylindrical  and  free  to  revolve.  The  plunger 
shown  at  A  will  follow  only  cam  profiles  which  have  gradual  lifts. 
The  plunger  shown  at  B  is  left  free  to  revolve  in  the  guide  bushing 
and  is  provided  with  a  flat  mushroom  head  which  serves  as  a  cam  fol- 
lower. The  type  shown  at  C  carries  a  roller  at  its  lower  end  and  may 
follow  very  irregular  cam  profiles  if  abrupt  lifts  are  desired.  While 
forms  A  and  B  are  the  simplest,  that  outlined  at  C  in  its  various  forms 
is  more  widely  used. 

The  illustrations  at  Fig.  77  show  some  of  the  different  possible 
methods  of  valve  operation.  At  A  the  application  of  a  rocker  arm 
and  tappet  rod  to  operate  an  overhead  valve  is  clearly  depicted.  The 
rocker  arm  is  interposed  in  order  that  the  upward  movement  of  the 
tappet  rod  will  'produce  a  down  movement  of  the  valve  stem.  The 
method  of  valve  operation  shown  at  B  is  possible  when  it  is  desired 
to  operate  both  valves  of  a  "  T  "  head  cylinder  from  a  common  cam 
shaft.  One  of  the  valves  is  lifted  directly  by  the  usual  cam  actuated 
plunger,  while  the  other  member  is  raised  from  its  seat  by  a  plunger 
operated  from  the  cam  through  a  centrally  pivoted  simple  lever.  At 
C  the  simplest  method  of  valve  operation  is  shown.  The  cylinder  cast- 
ing is  a  twin  "  L  "  form,  and  the  valves  are  placed  side  by  side  in  the 
pocket  at  one  side  of  center.  They  are  operated  directly  by  means  of 
simple  mushroom  head  plungers  guided  in  bushings  secured  in  bosses 
formed  integrally  with  the  cylinder  base.  These  plungers  bear  against 
the  lower  end  of  the  valve  stems. 

All  the  methods  in  which  levers  are  used  to  operate  valves  are  more 
or  less  noisy  because  clearance  must  be  left  between  the  valve  stem  and 
the  top  of  the  plunger.  The  space  must  be  taken  up  before  the  valve 
will  leave  its  seat,  and  when  the  engine  is  operated  at  high  speeds  the 
forcible  contact  between  the  plunger  and  valve  stem  produces  a  pro- 
nounced hammering  sound.  At  D  a  method  of  indirect  valve  opera- 
tion-is  shown.  The  main  purpose  is  to  obtain  silent  working  and  to 
permit  the  valves  being  arranged  in  any  convenient  position.  Instead 
of  using  direct  cam  action  against  the  end  of  the  valves,  the  valves  are 
lifted  from  their  seats  by  a  liquid  under  pressure.  The  cams  are 
placed  across  the  front  of  the  engine,  though  they  could  be  placed  at 


Rocker  Arm, 


Tappet  Rod 


B 


Fig,  77.— Defining  Different  Possible  Methods  of  Valve  Operation.  A— Over- 
head Valve  Actuated  by  Rocker  Arm,  Tappet  Rod  and  Roller  Type  Cam 
Follower.  B— Both  Valves  Operated  from  One  Cam,  "  T  "  Head  Cylinder. 
C— Valves  of  "  L  "  Type  Twin  Cylinder  Casting  Operated  by  Mushroom 
Type  Cam  Followers.  D — Suggested  Method  of  Indirect  Valve  Operation. 

151 


152  The  Modern  Gasoline  Automobile 

any  other  point  so  long  as  they  could  be  conveniently  driven  from  the 
crank  shaft. 

There  are  eight  cams,  one  for  each  valve,  and  under  each  cam  an 
oil  force  pump  is  placed.  This  is  connected  by  a  tube  to  a  plunger 
under  the  valve  stem.  Each  pipe  is  filled  with  oil,  and  when  the  cam 
operates  its  particular  pump  the  incompressible  liquid  in  the  pipe  is 
forced  against  the  plunger  under  the  valve  and  the  valve  is  lifted.  In- 
stead of  the  cam  pushing  the  tappet  and  the  plunger  pushing  the 
valve,  as  in  other  constructions  described,  the  cam  works  a  pump  and 
this  in  turn  a  tappet.  The  return  of  the  valve  stem  is  effected  by  the 
valve  springs  in  the  usual  way.  Each  oil  pump  is  also  provided  with 
a  return  spring  which  keeps  the  roller  on  top  of  the  pump  plunger 
bearing  against  the  cam.  The  whole  of  the  cam  action  is  in  an  oil 
bath  and  any  leakage  of  liquid  from  the  pipes  is  automatically  com- 
pensated for  through  a  simple  form  of  ball  valve.  Each  pipe  is 
always  full  of  oil  as  long  as  there  is  any  in  the  bath. 

As  it  is  not  possible  to  compress  the  liquid }  it  may  be  stated  broadly 
that  the  driving  effect  is  the  same  as  though  the  oil  pipes  were  filled 
with  steel  balls.  The  simile  is  not  a  correct  one,  because  the  fluid 
pressure  provides  a  softness  and  silence  of  action  which  could  not  be 
very  well  obtained  by  direct  operation.  It  is  also  expected  that  clear- 
ance between  the  valve  stem  and  operating  plungers  will  not  be  neces- 
sary because  the  slight  leakage  of  working  fluid  will  compensate  for 
any  expansion  of  the  valves  and  the  resulting  lengthening  of  the  stems 
automatically.  It  is  not  expected  that  this  method  of  valve  operation 
will  be  used  to  any  extent  because  the  mechanism  is  more  complicated 
than  when  simple  direct  lift  plungers  are  employed.  With  modern 
forms  of  plungers  which  are  provided  with  suitable  adjusting  features 
which  make  it  possible  to  maintain  a  minimum  clearance  between  valve 
stem  and  lifting  member,  the  valve  action  is  silent  enough  so  that  it 
would  not  pay  to  introduce  a  complicated  hydraulic  system  as  that 
described.  This  has  been  presented  mainly  to  show  that  valves  may  be 
operated  by  other  means  than  direct  cam  and  plunger  action. 

We  have  seen  that  the  method  of  valve  placing  has  material  bear- 
ing on  the  system  of  valve-actuating  mechanism  employed.  At  Fig. 
78  the  various  methods  of  valve  installation  are  presented  in  diagram- 
matic form  and  will  assist  the  reader  in  obtaining  a  clear  idea  of  the 


The  Modern  Gasoline  Automobile 


153 


valve  placings  most  commonly  used.  With  the  "  T  "  head  cylinder  as 
shown  at  A  separate  cam  shafts  are  usually  employed  and  the  valves, 
are  raised  by  direct  lift  plungers.  The  "L"  head  cylinder  as  de- 


Fig.  78. — Diagram  Showing  Forms  of  Cylinder  Demanded  by  Different  Valve 
Placings.  A — T  Head  Type,  Valves  on  Opposite  Sides.  B — L  Head 
Cylinder,  Valves  Side  by  Side.  C— L  Head  Cylinder,  One  Valve  in  Head, 
Other  in  Pocket.  D— Inlet  Valve  Over  Exhaust  Member,  Both  in  Side 
Pocket.  E— Valve-in-the-Head  Type  with  Vertical  Valves.  F— Inclined 
Valves  Placed  to  Open  Directly  into  Combustion  Chamber. 


154 


The  Modern  Gasoline  Automobile 


picted  at  B  calls  for  but  one  cam  shaft,  and  as  is  true  of  the  previous 
case  the  valves  may  be  lifted  directly  from  their  seats  by  a  simple  cam 
follower.  At  C  the  valve  location  demands  the  use  of  an  overhead 
rocker  arm  which  may  be  actuated  from  the  same  cam  shaft  which  is 
employed  to  raise  the  exhaust  valve  from  its  seat.  At  D  a  method 
of  valve  placing  is  shown  which  is  very  popular  on  small  motors  used 
for  motorcycle  propulsion.  The  inlet  valve  is  placed  directly  over 
the  exhaust  member  and  may  be  automatically  operated  or  may  be  de- 
pressed by  the  conventional  form  of  rocker  arm.  When  overhead  valves 
are  used,  as  shown  at  E,  two  rocker  arm  assemblies  are  needed  and 
both  valves  are  operated  from  a  common  cam  shaft.  With  the  form 
shown  at  F  having  inclined  valves  two  sets  of  rocker  arms  may  be 


Fig.  79. — Cam  Shaft  and  Valve  Operating  Plunger  Case  of  Hupp  Motor,  a  Separ- 
ate Member.    Note  Simple  Type  of  Cam  Follower. 

used  actuated  by  two  cam  shafts,  one  on  each  side  of  the  motor. 
Sometimes  a  single  rocker  arm  is  fulcrumed  at  the  center,  having 
one  extremity  bearing  on  each  valve  stem.  The  lever  is  rocked  by  a 
special  form  of  cam  provided  with  a  depression  as  well  as  a  raised 
portion.  When  the  tappet  rod  is  raised  it  may  depress  one  of  the 
valves,  whereas  when  the  cam  follower  drops  in  the  depression  of 
the  cam  the  other  end  of  the  rocker  arm  will  fall  and  open  the  other 
valve. 

A  cam  case  assembly,  such  as  used  on  the  Hupp  motor,  is  shown  at 


The  Modern  Gasoline  Automobile  155 

Fig.  79.  This  is  bolted  to  the  side  of  the  engine  base  and  the  large  gear 
attached  to  the  cam  shaft  is  driven  from  a  suitable  gear  on  the  crank 
shaft  at  .half  the  engine  speed.  The  cam  followers  are  the  simple  form 
shown  at  Fig.  76,  A.  They  are  provided  with  a  fiber  inset  at  their  top 
end  which  comes  into  contact  with  the  valve  stem.  The  use  of  this 
material  tends  to  reduce  noise  which  would  be  present  if  two  metals 
came  in  contact. 

Methods  of  Driving  Cam  Shaft. — Two  systems  of  cam  shaft  opera- 
tion are  used.  The  most  common  of  these  is  by  means  of  gearing  of 
some  form.  If  the  cam  shaft  is  at  right  angles  to  the  crank  shaft  it 
may  be  driven  by  worm,  spiral,  or  bevel  gearing.  If  the  cam  shaft  is 
parallel  to  the  crank  shaft,  simple  spur  gear  or  chain  connection  may 
be  used  to  turn  it.  At  Fig.  80  a  conventional  system  of  cam  gears 
is  shown.  The  front  of  the  gear  case  has  been  removed,,  this  exposing 
the  gear  train  which  drives  the  cam  shaft  and  accessory  mechanism. 
A  small  gear  having  thirty-two  teeth  is  placed  on  the  crank  shaft. 
This  engages  a  larger  member  having  sixty-four  teeth  turning  it  at 
one-half  its  speed.  This  large  gear  is  securely  fastened  to  a  flange 
on  the  cam  shaft  by  three  bolts.  At  the  right  an  idler  gear  meshes 
with  the  crank-shaft  gear  and  serves  to  transmit  motion  from  that 
member  to  the  small  gear  at  the  extreme  right  which  is  utilized  to 
drive  the  circulating  pump  shaft  and  the  magneto  employed  for 
ignition. 

While  gearing  is  more  commonly  used,  considerable  attention  has 
been  directed  of  late  to  silent .  chains  for  cam  shaft  operation.  The 
ordinary  forms  of  block  or  roller  chain  have  not  proven  successful  in 
this  application,  but  the  silent  chain,  which  is  in  reality  a  link  belt 
operating  over  toothed  pulleys,  has  demonstrated  its  worth.  The 
tendency  to  its  use  is  more  noted  on  foreign  motors  than  those  of 
American  design.  It  first  came  to  public  notice  when  employed  on 
the  Daimler-Knight  engine  for  driving  the  small  auxiliary  crank 
shafts  which  reciprocated  the  sleeve  valves. 

At  Fig.  81  two  efficient  cam  shaft  drives  are  illustrated.  That  at 
A  is  furnished  on  the  Wolseley  1912  motors.  It  will  be  observed  that 
the  small  gear  on  the  crank  shaft  is  coupled  to  a  larger  gear  on  the 
cam  shaft  by  one  chain,  while  a  separate  gear  wheel  and  chain  drives 
the  magneto  from  the  cam  shaft.  The  sprockets  are  so  proper- 


156 


The  Modern  Gasoline  Automobile 


tioned  that  the  cam  shaft  revolves  at  half  the  engine  speed,  while 
the  magneto  is  speeded  up  so  it  will  have  the  same  speed  as  the 
crank  shaft. 


r 


CAMSHAFT 
GEAR 


CRANKSHAFT 
GEAR 


Fig.  80.— Front  View  of  Warren-Detroit  '•  30  "  Motor  with  Timing  Gear  Case 
Cover  Removed  to  Show  Arrangement  of  Cam  Shafts  and  Water  Pump 
Driving  Gears. 


The  Modern  Gasoline  Automobile 


157 


At  Fig.  81,  B,  the  silent  chain  drive  on  the  White  &  Poppe  engines 
is  shown.  This  installation  is  similar  in  the  main  to  that  previously 
described,  and  further  description  is  not  needed.  The  advan- 
tages cited  for  the  application  of  chains  are,  first,  silent  operation 
which  obtains  even  after  the  chains  have  worn  considerably:  second, 
in  designing  it  is  not  necessary  to  figure  on  maintaining  certain  abso- 
lute center  distances  between  the  crank  shaft  and  cam  shaft  sprockets, 


Silent 


np 
Shaft 


Fig.  81.— Showing  Use  of  Silent  Chain  Connection  Between  Crank  Shaft  and 
Cam  Shaft,  and  also  for  Driving  Water  Pump  and  Magneto  Shafts. 
A— Chain  Drive  on  Wolseley  (English)  1912  Motor.  B— Method  of 
Using  Silent  Chains  on  White  &  Poppe  (English)  Power  Plant. 

as  would  be  the  case  if  conventional  forms  of  gearing  were  used.  On 
some  forms  of  motor  employing  gears,  three  and  even  four  members 
are  needed  to  turn  the  cam  shaft.  With  a  chain  drive  but  two  sprock- 
ets are  necessary,  the  chain  forming  a  flexible  connection  which  per- 
mits the  driving  and  driven  members  to  be  placed  at  any  distance 
apart  that  the  exigencies  of  the  design  demand.  When  chains  are 
used  it  is  advised  that  some  means  for  compensating  chain  slack  be 
provided  or  the  valve  timing  will  lag  when  chains  are  worn.  Many 
combination  drives  may  be  worked  out  with  chains  that  would  not  be 
possible  with  other  forms  of  gearing.  It  is  expected  that  there  will  be 
a  gradual  tendency  on  the  part  of  American  designers  to  incorporate 
the  silent  chain  drive  in  their  product. 


158  The  Modern  Gasoline  Automobile 

Valve  Springs. — Another  consideration  of  importance  is  the  use 
of  proper  valve  springs,  and  particular  care  should  be  taken  with  those 
of  automatic  valves.  The  spring  must  be  weak  enough  to  allow  the 
valve  to  open  when  the  suction  is  light  and  must  be  of  sufficient 
strength  to  close  it  in  time  at  high  speeds.  It  should  be  made  as  large 
as  possible  in  diameter  and  with  a  large  number  of  convolutions,  in 
order  that  fatigue  of  the  metal  be  obviated,  and  it  is  imperative  that 
all  springs  be  of  the  same  strength  when  used  on  a  multiple-cylinder 
engine.  On  the  exhaust  valve  the  spring  must  be  strong  enough  so 
that  the  valve  will  not  be  sucked  in  on  the  inlet  stroke.  It  should 
be  borne  in  mind  that  if  the  spring  is  too  strong  a  strain  will  be 
imposed  on  the  valve-operating  mechanism  and  a  hammering  action 
produced  which  may  cause  deformation  of  the  valve  seat.  Only  pres- 
sure enough  to  insure  that  the  operating  mechanism  will  follow  the 
cam  is  required.  It  is  common  practice  to  make  the  inlet  and  exhaust 
valve  springs  of  the  same  tension  when  the  valves  are  of  the  same  size 
and  both  mechanically  operated.  This  is  done  merely  to  simplify 
manufacture  and  not  because  it  is  necessary  for  the  inlet  valve  spring 
to  be  as  strong  as  the  other. 

Piston  and  Rotary  Valve  Motors. — Mention  has  been  previously 
made  of  the  interest  obtaining  in  various  forms  of  valves  which  permit 
more  silent  operation  than  the  conventional  poppet  type.  The  main 
features  of  the  Knight  engine  and  its  advantages  have  been  considered, 
but  a  more  complete  description  of  the  valve  action  may  be  timely. 
The  sectional  view  through  the  cylinder  at  Fig.  82  shows  the  Knight 
sliding  sleeves  and  their  actuating  means  very  clearly.  The  diagrams 
at  Fig.  83  show  graphically  the  sleeve  movements  and  their  relation 
to  the  crank  shaft  and  piston  travel.  At  A  the  piston  has  reached  the 
top  of  the  exhaust  stroke  and  the  exhaust  port  is  barely  open.  The 
inlet  port  is  just  beginning  to  open.  At  B  the  piston  is  about  two- 
thirds  down  on  the  inlet  stroke  and  the  inner  sleeve  has  moved  down, 
this  bringing  the  two  ports  in  alignment.  This  movement  of  the 
sleeve  Jias  closed  off  the  exhaust  port.  At  C  the  position  of  the  sleeves 
at  the  end  of  the  intake  stroke  is  shown.  The  inner  sleeve  continues 
to  go  up,  the  outer  sleeve  is  still  moving  down.  Here  we  see  the  inlet 
port  is  almost  closed;  the  exhaust  port  entirely  so.  D  represents  the 
position  assumed  by  the  sleeves  at  the  end  of  the  compression  stroke, 


The  Modern  Gasoline  Automobile 


159 


both  ports  are  closed  and  the  compressed  charge  is  ready  for  ignition. 
At  E  the  piston  has  covered  about  three-quarters  of  the  power  stroke 


Spark  p/ug 


Relief  Cock 


Cylinder  Head 


Sleeue 


Fig.  82.— Section  Through  Cylinder  of  Knight  Motor,  Showing  Important  Parts 

of  Valve  Motion. 

and  the  exhaust  port  begins  to  open.     Both  sleeves  are  now  traveling 
down.     At  F  the  piston  has  reached  the  bottom  of  the  power  stroke 


160 


The  Modern  Gasoline  Automobile 


and  the  exhaust  port  is  almost  fully  opened.  At  G  the  piston  is  mov- 
ing upward  and  the  hurned  gas  is  being  discharged  through  the  fully 
opened  exhaust  port.  At  H  the  piston  has  started  down  on  the  intake 
stroke.  The  exhaust  port  is  fully  closed  and  the  inlet  port  is  just  be- 


tnlet 


Fig.  83.— Diagram  Showing  Relative  Movement  of  Sleeves  and  Cam  Shaft  of 
Knight  Type  Motor.  Note  Port  Opening  at  Various  Piston  Positions. 
Shaded  Portions  of  Sleeves  Represent  Ports. 

ginning  to  open.  The  action  may  be  summed  up  as  follows :  The  inlet 
port  begins  to  open  when  the  lower  edge  of  the  opening  of  the  outside 
sleeve  which  is  moving  down  passes  the  top  of  the  slot  in  the  inner 
member  also  moving  downwardly.  The  inlet  port  is  closed  when  the 


The  Modern  Gasoline  Automobile  161 

lower  edge  of  the  slot  in  the  inner  sleeve  which  is  moving  up  passes 
the  top  edge  of  the  port  in  the  outer  sleeve  which  is  also  moving 
toward  the  top  of  the  cylinder.  The  inlet  opening  extends  over  two 
hundred  degrees  of  crank  motion.  The  exhaust  port  is  uncovered 
slightly  when  the  lower  edge  of  the  port  in  the  inner  sleeve  which  is 
moving  down  passes  the  lower  edge  of  the  portion  of  the  cylinder  head 
which  protrudes  in  the  cylinder.  When  the  top  of  the  port  in  the  outer 
sleeve  traveling  toward  the  bottom  of  the  cylinder  passes  the  lower 
edge  of  the  slot  in  the  cylinder  wall  the  exhaust  passage  is  closed. 
The  exhaust  opening  extends  over  a  period  corresponding  to  about  two 
hundred  and  forty  degrees  of  crank  motion. 

The  Valveless  Miesse  Engine. — The  title  given  to  this  engine  is 
hardly  correct  as  it  is  not  a  valveless  engine,  but,  as  a  glance  at  the 
illustration  Fig.  84  will  show,  it  is  a  combination  of  the  single  sleeve 
and  piston  valve  forms.  In  the  views  presented,  B  is  the  single  sleeve 
in  which  the  port  D  is  formed ;  A  is  the  inlet  and  E  the  exhaust  open- 
ing. The  part  designated  by  C  is  termed  the  "  distribution  "  piston. 
Both  the  inlet  and  exhaust  passages  open  into  and  lead  from  the  small 
cylinder  in  which  the  piston  C  reciprocates.  This,  as  well  as  the  sleeve 
B,  derives  its  motion  from  the  cam  or  valve  shaft  through  connecting 
rods.  But  little  explanation  is  necessary  to  describe  the  operation  of 
the  valves  and  their  effect.  At  A  the  relative  positions  of  the  sleeve 
and  piston  valve  during  the  induction  stroke  are  shown.  It  will  be 
seen  that  the  port  D  in  the  sleeve  coincides  with  the  slot  in  the  cylinder 
proper,  and  the  pjston  valve  C  is  in  such  position  that  while  the  mix- 
ture has  free  access  from  A  to  the  cylinder  the  exhaust  port  E  is  cut 
off  therefrom.  At  B  the  relative  positions  of  the  sleeve  and  piston 
valve  during  the  explosion  stroke  are  shown.  The  port  D  in  the 
sleeve  has  moved  up  above  the  opening  in  the  cylinder  wall  while  the 
latter  is  there  closed  against  any  possible  escape  of  gas  by  the  cylin- 
drical head  of  the  piston  valve  C.  The  position  of  the  parts  on  the 
exhaust  stroke  are  shown  at  C.  The  piston  valve  has  risen  still  fur- 
ther, closing  the  induction  passage  A  which  leads  the  fresh  gases  to  the 
cylinder  and  at  the  same  time  has  made  it  possible  for  the  exhaust 
products  to  be  discharged  beneath  it  through  the  opening  E  which  is 
in  connection  with  the  exhaust  manifold. 

The  advantages  claimed  for  this  design  are  the  use  of  a  single 


162 


The  Modern  Gasoline  Automobile 


sleeve,  cooling  of  the  sleeve  cylinder  ports  and  piston  valve  by  the 
incoming  mixture  on  the  induction  stroke  and  the  protection  of  the 


B 


Fig.  84. — Sectional  Views  Showing  Action  of  Miesse  Combination  Sleeve  and 
Piston  Valve  at  Different  Points  in  Cycle  of  Engine  Operation. 


piston  valve  from  contact  with  the  exploded  charge  during  the  power 
stroke.     It  is  said  that  the  exhaust  gases  are  discharged  through  the 


The  Modern  Gasoline  Automobile  163 

lower  orifice  rather  than  the  upper  one  in  order  that  no  pressure  be 
exerted  upon  the  head  of  the  piston  and  upon  its  connecting  rod  and 
crank  pin  bearings.  By  passing  the  exhaust  gases  which  have  con- 
siderable pressure  between  the  upper  and  lower  portions  of  the  piston 
valve  the  latter  is  balanced  during  exhaust  period  by  the  products  of 
the  combustion  under  pressure.  The  valve  shaft,  which  is  the  small 
auxiliary  crank  shaft  reciprocating  the  sleeve  and  piston,  is  supported 
on  five  bearings  and  is  driven  by  a  silent  chain  connection  from  the 
main  crank  shaft. 

The  Itala  Rotary  Valve  Motor. — A  type  of  rotary  valve  which  is 
said  to  be  efficient  is  depicted  at  Fig.  85.  This  is  used  in  the  Itala 
engine  and  has  features  of  merit.  This  motor  does  not  differ  much 
in  appearance  from  the  ordinary  poppet  valve  type.  The  cylinders  are 
cast  in  pairs  with  a  projection  at  one  side  which  acts  as  a  cylinder 
for  the  valve.  Provision  is  made  for  water  circulation  around  this 
chamber  and  the  valve  is  also  formed  in  such  a  way  that  water  may 
be  circulated  through  it.  But  two  valves  are  employed,  one  for  each 
pair  of  cylinders,  and  these  two  members  take  the  place  of  the  eight 
valves  used  on  the  poppet  engine.  The  valve  driving  shaft,  which  is 
placed  similar  to  the  conventional  cam  shaft,  turns  the  vertical  shaft 
to  which  the  valves  are  attached  by  helical  gears.  There  is  but  one 
port  in  each  cylinder  which  provides  the  means  of  communication 
between  the  valves  and  combustion  chamber,  this  alternately  serving 
the  purpose  of  inlet  and  exhaust  port.  The  manifolds  are  on  opposite 
sides  of  the  engine.  The  gas  enters  the  base  of  each  valve  chest  and 
the  inert  products  pass  from  the  top  of  the  valve  chamber  by  a  pecu- 
]iar  cored  passage  in  the  cylinder  casting.  The  rotary  valve  is  made 
of  cast  iron  and  carries  a  number  of  packing  rings.  Each  valve  has 
four  vertical  openings;  two  for  the  fresh  gases,  the  others  for  the 
burned  product.  These  openings  are  arranged  so  that  there  is  one 
inlet  and  one  exhaust  port  registering  with  the  openings  in  the  re- 
spective cylinders.  The  exhaust  ports  are  wider  than  the  inlet  open- 
ings, because  a  longer  period  of  opening  is  required  for  the  exhaust. 

The  views  at  Fig.  85  show  the  operation  of  the  valve  clearly.  A 
depicts  its  position  at  the  beginning  of  the  intake  stroke,  the  fresh  gas 
entering  from  the  bottom  passes  through  the  interior  of  the  valve  and 
into  the  combustion  chamber.  The  smaller  sectional  views  show  a 


Fig.  85.— Defining  Action  of  Peculiar  Rotary  Valve  Used  in  Latest  Itala  (Italian 

Motor. 


164 


The  Modern  Gasoline  Automobile 


165 


plan  of  the  cylinder  and  valve  chest.  Referring  to  these  it  will  be  seen 
that  the  valve  which  is  rotating  in  the  direction  of  the  arrow  is  just 
beginning  to  uncover  the  port  in  the  cylinder.  At  B  conditions  dur- 
ing the  compression  stroke  are  shown.  The  port  in  the  cylinder  is 


Value  Gear 

Driving  Pinion 


Port 


Value  Shaft 


Fig.  86.— Partial  Section  of  Reynolds  Rotary  Valve  Motor  Cylinder,  Showing 
Method  of  Rotating  Simple  Disk  Valve  and  Ports  in  Cylinder  Head. 

closed  by  the  solid  wall  of  the  valve.  At  C  the  position  of  the  valve 
during  the  power  stroke  is  shown.  It  will  be  observed  that  the  open- 
ing in  the  cylinder  is  still  closed  by  the  valve  wall.  At  D  the  condi- 


166  The  Modern  Gasoline  Automobile 

tions  during  the  exhaust  stroke  are  outlined.  The  valve  has  revolved 
so  that  the  exhaust  port  therein  is  in  communication  with  the  exhaust 
pipe  at  the  top  of  the  cylinder  and  the  port  of  the  comhustion  cham- 
her.  This  permits  the  inert  gases  to  leave  the  cylinder  freely.  Careful 
study  of  the  drawings  will  show  that  the  gas  flow  is  easy  and  that  there 
are  no  sharp  corners  to  impede  the  gases  as  they  enter  or  leave  the 
cylinders. 

The  Reynolds  Rotary  Valve  Motor. — The  Eeynolds  motor,  a  sec- 
tional view  through  one  of  its  cylinders  being  shown  at  Fig.  86,  has 
not  been  used  to  any  extent  in  automobile  service,  but  has  proven 
thoroughly  practical  in  marine  applications.  The  valve  consists  of  a 
flat  disk  seating  directly  against  the  top  of  the  combustion  chamber. 
It  is  turned  by  a  shaft  which  extends  through  a  boss  on  top  of  the 
cylinder  head  and  which  is  driven  direct  from  the  crank  shaft  by  gear- 
ing at  half  the  motor  speed.  The  valve  has  a  port  cut  into  it  of  the 
keystone  shape,  clearly  shown  in  illustration,  this  registering  suc- 
cessively with  openings  in  the  cylinder  head.  The  valve  mechanism 
is  said  to  be  very  quiet,  and,  as  will  be  seen  at  Fig.  87,  the  motor  is  a 
very  compact  design.  A  disadvantage  is  cited  that  the  force  of  the 
explosion  keeps  the  valve  disk  tight  against  the  seat,  this  tending  to 
cause  considerable  resistance  to  its  motion.  It  is  claimed  that  no 
difficulty  is  experienced  from  this  source,  and  that  an  oil  film  is  main- 
tained positively  between  the  valve  disk  and  its  seat  so  that  it  turns 
with  minimum  friction. 

Other  Rotary  Valve  Types. — Various  other  forms  employing  rotary 
valves  have  been  devised,  and  some  of  these  which  are  said  to  have 
been  used  in  a  practical  way  are  shown  at  Fig.  88.  That  at  A  is 
known  as  the  Mead.  This  is  a  four-cylinder  motor  with  two  long 
cylindrical  valves  extending  along  opposite  sides  of  the  cylinders  in 
close  connection  with  the  combustion  chamber.  These  cylinders  have 
ports  cut  through  them  at  distances  equal  to  the  center  line  of  tho 
cylinders  and  are  suitably  spaced  so  that  the  ports  in  the  cylinders  are 
uncovered  in  proper  succession.  One  of  the  drums  serves  to  control 
the  inlet  ports ;  the  other  regulates  the  exhaust  openings.  The  valves 
are  driven  at  one-quarter  crank-shaft  speed  by  suitable  gearing. 

The  type  shown  at  B  is  a  French  design  which  differs  from  the 
Reynolds  motor  previously  described  only  in  the  shape  of  the  rotary 


The  Modern  Gasoline  Automobile 


167 


valve  member  which  is  conical  instead  of  flat.  The  parts  are  shown 
as  follows :  A  is  the  rotary  valve  member ;  B  is  the  gas  passage,  and  D 
is  a  port  in  the  valve  member.  The  small  view  presented  below  the 
vertical  section  is  a  plan  showing  the  disposition  of  the  ports.  The 


Value  Gear 


Driving  Pinion 


Fig.  87.— Part  Section  of  Reynolds  Rotary  Valve  Motor,  Showing  Practical 
Application  of  Ported  Disk  in  Controlling  Gas  Passages.  Note  Compact 
Design  of  Cylinder  Block  and  Two-Bearing,  Four-Throw  Crank  Shaft. 

same  lettering  applies  as  above.  If  the  cone  turns  in  the  direction  of 
the  arrow,  B  is  the  exhaust  port  and  C  the  intake  port,  while  D  repre- 
sents the  opening  in  the  valve.  The  form  shown  at  C  is  a  modification 
of  that  depicted  at  B.  Two  conical  valves  are  used  instead  of  one, 


168 


The  Modern  Gasoline  Automobile 


Exhaust 


Driving  Gear 

Driven  Gear 


Gas  Passage 


Fig.  88. — Unconventional  Forms  of  Rotary  Valve  Motors  Designed  to  Meet  the 
Present  Day  Demand  for  Silent  Valve  Action.  A — Mead  Motor  Using  Two 
Revolving  Cylindrical  Valves,  One  at  Each  Side  of  Cylinder.  B— Single 
Ported  Cone  Valve.  C — Application  of  Two  Single  Ported  Cones,  One 
Superposed.  D— Use  of  Distinct  Valves,  One  for  Inlet  Port,  the  Other  to 
Govern  Exhaust  Passage. 


" 


The  Modern  Gasoline  Automobile  169 

these  being  turned  in  opposite  directions  by  suitable  gears.  It  is 
claimed  that  this  gives  a  more  rapid  port  opening  than  when  a  single 
valve  is  employed.  Sometimes  when  two  conical  valve  members  are 
used  they  are  placed  side  by  side,  as  shown  at  D,  one  of  these  serving 
exclusively  for  the  exhaust ;  the  other  for  the  inlet.  The  objection  to 
this  construction  is  that  owing  to  the  smaller  size  of  the  cone  the  ports 
are  more  limited  in  area  than  when  a  single  valve  member  is  employed. 

The  Sphinx  Ring  Valve  Motor. — One  of  the  designs  which  has  been 
used  successfully  and  which  employs  a  ring  valve  in  place  of  the  usual 
poppet  valves  is  called  the  Sphinx  motor.  It  is  claimed  that  all  the 
advantages  of  the  sliding  sleeve  types  are  obtained  with  much  less  com- 
plication. In  this  motor  a  split  ring  reciprocated  by  a  bell  crank 
serves  to  uncover  the  intake  and  exhaust  ports.  The  construction  of 
this  member,  as  well  as  the  actuating  bell  crank,  return  spring  and 
cam  shaft  are  clearly  shown  at  Fig.  89.  In  the  cylinder  walls,  and 
near  the  head,  two  annular  chambers  are  provided,  these  forming  the 
intake  and  exhaust  ports.  Within  the  cylinder  is  a  split  ring  having 
sufficient  face  depth  to  cover  both  the  intake  and  exhaust  ports,  but 
having  the  necessary  reciprocating  motion  t»  allow  it  to  uncover  either 
one  or  the  other  of  the  ports  as  required  to  insure  the  admission  of 
the  fuel  and  the  discharge  of  the  spent  gases.  In  its  central  position, 
shown  at  Fig.  89,  B  and  C,  the  split  ring  covers  the  two  ports,  pro- 
viding a  gas-tight  chamber ;  on  being  moved  down,  as  depicted  at  A,  it 
uncovers  the  intake  port  and  closes  the  exhaust,  and  on  being  raised, 
outlined  at  D,  it  opens  the  exhaust  and  closes  the  intake. 

Being  split,  its  extensibility  assures  gas-tightness,  the  degree  of 
tightness  being  in  proportion  to  the  pressure  in  the  cylinder,  while 
leakage  around  the  ports  is  impossible  at  any  time.  Its  movement  is 
slight,  being  less  than  one  inch  for  a  motor  of  3. 9-inch  by  5.5-inch  bore 
and  stroke,  and  the  intake  port  being  above  the  ring,  this  latter  is 
swept  by  the  fresh,  cool  gases  at  every  induction  stroke  and  conse- 
quently maintained  at  a  moderate  temperature. 

This  design  particularly  lends  itself  to  an  easily  produced  and 
clean  monobloc  casting,  and  has  the  further  advantage  of  giving  a 
compact  combustion  chamber  without  pockets  and  with  unusually 
large  valve  area.  On  the  ordinary  type  of  motor  with  valves  on  one 
or  both  sides  any  increase  in  the  valve  diameter  involves  a  proper- 


170 


The  Modern  Gasoline  Automobile 


tional  increase  in  the  size  of  the  pocket  with  a  decrease  of  thermal 
efficiency. 

The  split  sliding  ring,  or  sleeve,  which  in  the  "  Sphinx  "  replaces 
the  pair  of  poppet  valves  of  the  ordinary  motor,  and  the  costly  concen- 


Value  Return  Spring 


Inlet  Port 
Split  Ring 
Exhaust  Port 


Distribution  Gears 
Piston 


Compression. 


Reduction 
Gears 


Explosion 


Oil  Pump 


Fig.  89.— Part  Section  of  Sphinx  Valveless  Motor  in  which  Poppet  Valves  are 
Replaced  by  a  Split  Ring  which  Reciprocates  in  the  Cylinder  Head,  Opening 
and  Closing  the  Gas  Ports  as  it  Moves  Up  and  Down.  A— Inlet  Ports  Open. 
B  and  C— All  Ports  Closed.  D — Exhaust  Ports  Open. 

trie  sleeves  in  motors  of  the  sliding  valve  type,  is  shown  in  Fig.  89.  It  is 
a  gray  iron  casting,  having  a  face  depth  of  one  and  a  half  inches  for  a 
motor  of  3.9-inch  by  5.5-inch  bore  and  stroke,  and  provided  with  a  hoi- 


The  Modern  Gasoline  Automobile  171 

low  spindle  or  bearing  block  for  the  rocker  arm.  As  will  be  seen  from  the 
illustration,  the  depth  of  the  ring  is  greater  around  the  hollow  spindle 
than  at  any  other  point,  this  increased  depth  being  necessary  to  cover 
the  port  through  which  the  rocker  arm  is  passed  from  the  outside 
to  the  inside  of  the  cylinder.  The  face  depth  at  this  point  is  suffi- 
cient to  assure  the  covering  of  this  port  whatever  the  position  of 
the  split  ring;  in  other  words,  this  slot  in  the  cylinder  wall  is  never 
uncovered. 

By  means  of  a  bell  crank,  the  long  arm  of  which  operates  in  the 
socket  of  the  ring  valve,  and  an  ordinary  type  of  cam  shaft  the  neces- 
sary reciprocating  motion  of  the  ring  is  obtained  to  allow  the  different 
phases  of  a  four-cycle  motor.  One  of  the  most  valuable  features  of 
this  motor  is  the  large  valve  area  obtainable  without  the  complication 
attending  the  use  of  large  diameter  poppet  valves  and  without  the  big 
pockets  necessary  with  motors  of  the  "  L  "  or  "  T  "  type. 

The  poppet  valve  spring  must  be  of  sufficient  strength  to  correctly 
seat  the  valve  at  high  motor  speeds.  If  a  weak  spring  is  used  it  will 
not  have  time  to  return  the  valve  to  its  siting  before  it  will  be  again 
lifted  by  the  cam  and  there  is  loss  of  power.  The  spring  used  on  the 
"  Sphinx  "  motor  need  only  be  strong  enough  to  balance  the  weight  of 
the  split  ring,  for  it  is  only  responsible  for  its  return  and  in  no  way 
for  its  proper  seating.  Further,  as  each  upward  movement  of  the 
ring  is  followed  by  the  induction  stroke  of  the  motor,  the  work  of  the 
spring  is  relieved  by  the  inrushing  of  the  gases.  In  other  words,  the 
suction  of  the  gas  around  the  ring  tends  to  draw  it  down,  just  as  an 
automatic  intake  valve  is  drawn  down  on  the  suction  stroke  of  the 
motor.  The  spring,  then,  need  only  be  sufficiently  strong  to  keep  the 
roller  in  contact  with  the  face  of  the  cam,  and  as  it  is  carried  in  an 
independent  housing  and  not  subjected  to  a  high  temperature,  its  life 
is  practically  indefinite. 

Darracq  Rotary  Distributor  Motor. — In  the  Darracq  power  plant 
which  is  shown  at  Fig.  90,  the  gases  enter  through  a  rotary  member  of 
D  section,  which  is  placed  horizontally  along  the  side  of  the  cylinder 
head  and  parallel  with  the  crank  shaft.  This  distributor  is  approxi- 
mately two-thirds  the  diameter  of  the  cylinder  and  revolves  on  large 
annular  ball  bearings,  one  placed  at  each  end.  One  member  serves  to 
control  both  intake  and  exhaust  openings.  This  is  accomplished  by 


172 


The  Modern  Gasoline  Automobile 


providing  the  barrel-shaped  chamber  in  which  the  valve  revolves  with 
three  ports  for  each  cylinder.  One  of  these  provides  communication 
between  the  valve  case  and.  the  combustion  chamber,  the  others  serve 
for  intake  and  exhaust  passages. 


Spark  Plug 

Inlet 


Piston 


Connecting 
Rod 


Rotary  Valve 


Fig.  90. — Diagram  Illustrating  Action  of  Darracq  (French)  D  Form  Rotary  Valve 
Motor.  A — Piston  at  Beginning  of  Induction  Stroke.  B — Piston  at  Incep- 
tion of  Compression  Stroke.  C — Piston  in  Position  for  Receiving  Explosion 
Impact.  D— Valve  Position  at  Start  of  Exhaust  Period. 


The  Modern  Gasoline  Automobile  173 

As  the  valve  rotates  the  cylinder  is  placed  in  communication  with 
either  the  intake  or  exhaust  passages  and  the  valve  is  driven  by  suit- 
able gearing  at  one-half  the  engine  speed,  as  is  the  case  with  the  con- 
ventional cam  shaft.  The  various  valve  positions  are  clearly  shown  at 
Fig.  90.  A  corresponds  to  the  suction  stroke;  and  the  piston  is  shown 
starting  to  uncover  the  port  leading  from  the  valve  chamber  into  the 
cylinder.  The  rotary  valve  is  also  uncovering  the  intake  port.  By  the 
time  the  top  of  the  piston  reaches  the  bottom  of  the  passage  communi- 
cating between  combustion  and  valve  chambers,  the  inlet  opening  is 
uncovered  and  the  gas  rushes  into  the  cylinder.  At  B  it  will  be  seen 
that  the  valve  has  closed  the  passage  leading  from  the  cylinder,  and  as 
the  piston  rises,  the  gas  previously  inspired  is  compressed.  The  posi- 
tion of  the  piston  when  it  has  reached  the  end  of  the  compression 
stroke  is  shown  at  C.  At  this  position  the  compressed  charge  is 
ignited.  It  will  be  noted  that  the  piston  covers  the  port  leading  into 
the  valve  chamber,  and  that  the  valve  is  thus  protected  from  the  direct 
heat  of  combustion.  At  D  the  position  of  the  valve  at  the  inception  of 
the  exhaust  stroke  is  shown,  and  it  is  about  to  uncover  the  port  lead- 
ing from  the  cylinder  to  the  valve  chamber  and  permit  the  exhaust 
gases  to  flow  out  through  suitable  openings.  The  heat  evolved  during 
the  first  intervals  of  the  explosion,  at  which  point  the  maximum  tem- 
perature obtains,  is  kept  from  the  valve  and  simplifies  the  problem  of 
lubrication.  It  will  be  evident  that  with  this  construction  a  small  por- 
tion of  the  inert  gases  are  retained  in  the  combustion  chamber,  but  it 
is  claimed  by  those  favoring  this  construction  that  this  does  not  con- 
stitute as  serious  defect  in  practice  as  theoretical  considerations  might 
indicate. 

The  Hewitt  Piston  Valve  Motor. — A  type  of  motor  in  which  true 
piston  valves  are  used  successfully  is  shown  in  section  at  Fig.  91.  This 
is  the  Hewitt,  a  pioneer  form  of  English  derivation.  Two  piston 
valves  are  provided  for  each  cylinder;  one  for  the  intake,  the  other  to 
regulate  the  exhaust  passage.  They  are  placed  adjacent  to  each  other 
on  the  same  side  of  the  motor,  and  are  inclined  toward  the  top.  A 
small  crank  shaft  revolving  at  one-half  the  speed  of  the  main  crank 
shaft  is  employed  to  operate  the  piston.  Each  of  these  piston  valves 
are  simply  smaller  trunk  pistons  similar  in  type  to  those  used  in  the 
cylinder  proper,  reciprocating  in  their  distinct  small  water-cooled  cyl- 


174 


The  Modern  Gasoline  Automobile 


Exhaust  Piston 


Main  Piston 


inder.  Piston  rings  of  the  conventional  pattern  are  used  to  maintain 
a  gas-tight  joint,  as  is  the  case  with  the  main  piston.  The  fresh  gas 
manifold  is  coupled  to  the  side  of  one  valve  cylinder  and  the  exhaust 

piping  with  the 
side  of  the  other 
valve  chamber. 
The  timing  of 
both  intake  and 
exhaust  valves  is 
such  that  they 
receive  a  portion 
of  the  explosive 
impulse,  which 
drives  them 
downward  and 
tends  to  make 
them  partially 
self  -  operating. 
When  the  explo- 
sion occurs,  both 
valve  pistons  are 
at  the  top  of 
their  cylinders 


Main 
Connecting  Rod 


Crankshaft 


Value  Shaft 


Fig.  91.— Section  of  Hewitt  Piston  Valve,  Motor  Cylinder 
and  Valve  Chest. 

and  receive  part 

of  the  impact.  On  the  compression  stroke  both  pistons  move  up,  the 
exhaust  member  moving  ahead  of  the  other.  The  piston  valves  are 
lubricated  by  splash  just  as  the  main  piston  chamber.  These  pistons 
have  comparatively  long  stroke,  about  two-thirds  that  of  the  working 
piston.  The  various  piston  positions  during  the  cycle  of  operation  are 
clearly  shown  in  diagrams  at  Fig.  92,  the  valves  being  shown  at  oppo- 
site sides  of  the  cylinder  to  make  their  action  clearer.  At  A  the  main 
piston  is  part  way  down  on  the  intake  stroke,  and  the  inlet  piston  lias 
uncovered  the  slots  leading  from  the  gas  manifold  to  the  combustion 
chamber.  The  exhaust  is  fully  closed.  At  B  the  rrfain  piston  is  start- 
ing to  go  up  on  the  compression  stroke  and  both  inlet  and  exhaust 
ports  are  fully  closed  by  their  respective  pistons.  At  C  the  explosion 
has  taken  place  and  the  three  pistons  are  being  driven  down  in  the 


The  Modern  Gasoline  Automobile 


175 


directions  indicated  by  the  arrow.  At  D  the  exhaust  piston  has  un- 
covered the  series  of  holes  which  provide  communication  between  the 
combustion  chamber  and  the  manifold,  while  the  inlet  piston  covers 
fully  the  slots  it  controls.  It  is  claimed  that  this  four-cylinder  piston 
valve  motor  has  superior  torque  to  that  obtained  from  a  similar  power 
plant  using  poppet  valves. 


Inlet  - 


Exhaust 


Fig.  92. — Hewitt  Piston  Valve  Motor  Action  Outlined  Graphically.     A — Suction 
Stroke.     B — Compression.     C — Explosion.     D — Exhaust. 

Valve  Timing. — It  is  in  valve  timing  that  the  greatest  difference 
of  opinion  prevails  among  engineers  and  it  is  rare  that  one  will  see  the 
same  formula  in  different  motors.  It  is  true  that  the  same  timing 
could  not  be  used  with  motors  of  different  construction,  as  there  are 
many  factors  which  determine  the  amount  of  lead  to  be  given  to  the 


176  The  Modern  Gasoline  Automobile 

valves.  The  most  important  of  these  is  the  relative  size  of  the  valve 
to  the  cylinder  bore,  the  speed  of  rotation  it  is  desired  to  obtain, 
the  fuel  efficiency,  the  location  of  the  valves,  and  other  factors  too 
numerous  to  mention. 

Most  of  the  readers  should  be  familiar  with  the  cycle  of  operation 
of  the  internal  combustion  motor  of  the  four-stroke  type,  and  it  seems 
unnecessary  to  go  into  detail  except  to  present  a  review.  The  first 
stroke  of  the  piston  is  one  in  which  a  charge  of  gas  is  taken  into  the 
motor;  the  second  stroke  which  is  in  reverse  direction  to  the  first  is 
a  compression  stroke,  at  the  end  of  which  the  spark  takes  place,  ex- 
ploding the  charge  and  driving  the  piston  down  on  the  third  or  expan- 
sion stroke,  which  is  in  the  same  direction  as  the  intake  stroke,  and 
finally,  after  the  piston  has  nearly  reached  the  end  of  this  stroke, 
another  valve  opens  to  allow  the  burned  gases  to  escape,  and  remains 
open  until  the  piston  has  reached  the  end  of  the  fourth  stroke  and  is 
in  a  position  to  begin  the  series  over  again.  The  ends  of  the  strokes 
are  reached  when  the  piston  comes  to  a  stop  at  either  top  or  bottom  of 
the  cylinder  and  reverses  its  motion.  That  point  is  known  as  a  center 
and  there  are  two  for  each  cylinder,  top  and  bottom  centers,  re- 
spectively. 

All  circles  may  be  divided  into  360  parts,  each  of  which  is  known 
as  a  degree,  and  in  turn  each  of  these  degrees  may  be  again  divided  into 
minutes  and  seconds,  though  we  need  not  concern  ourselves  with  any- 
Ihing  less  than  the  degree.  Each  stroke  of  the  piston  represents  180 
degrees  travel  of  the  crank,  because  two  strokes  represent  one  complete 
revolution  or  three  hundred  and  sixty  degrees.  The  top  and  bottom 
centers  are  therefore  separated  by  180  degrees.  Theoretically  each 
phase  of  a  four-cycle  engine  begins  and  ends  at  a  center,  though  in 
actual  practice  the  inertia  or  movement  of  the  gases  makes  it  neces- 
sary to  allow  a  lead  or  lag  to  the  valve,  as  the  case,  may  be.  If  a 
valve  opens  before  a  center,  the  distance  is  called  "  lead  " ;  if  it  closes 
after  a  center,  this  distance  is  known  as  "lag."  The  profile  of  the 
cams  ordinarily  used  to  open  or  close  the  valves  represents  a  consider- 
able time  in  relation  to  the  180  degrees  of  the  crank-shaft  travel, 
and  the  area  of  the  passages  through  which  the  gases  are  admitted 
or  exhausted  is  quite  small  owing  to  the  necessity  of  having  to 
open  or  close  the  valves  at  stated  times;  therefore,  to  open  an  ade- 


The  Modern  Gasoline  Automobile  177 

quately  large  passage  for  the  gases  it  is  necessary  to  open  the  valves 
earlier  and  close  them  later  than  at  centers. 

That  advancing  the  opening  of  the  exhaust  valve  was  of  value  was 
discovered  on  the  early  motors  and  is  explained  by  the  necessity  of 
releasing  a  large  amount  of  gas,  the  volume  of  which  has  been  greatly 
raised  by  the  heat  of  combustion.  When  the  inlet  valves  were  mechan- 
ically operated  it  was  found  that  allowing  them  to  lag  at  closing  en- 
abled the  inspiration  of  a  greater  volume  of  gas.  Disregarding  the 
inertia  or  flow  of  the  gases,  opening  the  exhaust  at  center  would  enable 
one  to  obtain  full  value  of  the  expanding  gases  the  entire  length  of  the 
piston  stroke,  and  it  would  not  be  necessary  to  keep  the  valve  open 
after  the  top  center,  as  the  reverse  stroke  would  produce  a  suction 
effect  which  might  draw  some  of  the  inert  charge  back  into  the  cylin- 
der. On  the  other  hand,  giving  full  consideration  to  the  inertia  of  the 
gas,  opening  the  valve  before  center  is  reached  will  provide  for  quick 
expulsion  of  the  gases,  which  have  sufficient  velocity  at  the  end  of  the 
stroke,  so  that  if  the  valve  is  allowed  to  remain  open  a  little  longer, 
the  amount  of  lag  varying  with  the  opinions  of  the  designer,  the 
cylinder  is  cleared  in  a  more  thorough  manner. 

Blowing  Back. — When  the  factor  of  retarded  opening  is  considered 
without  reckoning  the  inertia  of  the  gases  it  would  appear  that,  if  the 
valve  were  allowed  to  remain  open  after  center  had  passed  say  on  the 
closing  of  the  inlet,  the  piston  having  reversed  its  motion  would 
have  the  effect  of  expelling  part  of  the  fresh  charge  through  the  still 
open  valve  as  it  passed  inward  at  its  compression  stroke.  This  effect 
is  called  blowing  back  and  is  often  noted  with  motors  where  the  valve 
settings  are  not  absolutely  correct,  or  where  the  valve  springs  or  seats 
are  defective  and  prevent  proper  closing. 

This  factor  is  not  of  as  much  import  as  might  appear,  as  on  closer 
consideration  it  will  be  seen  that  the  movement  of  the  piston  as  the 
crank  reaches  either  end  of  the  stroke  is  less  per  degree  of  angular 
movement  than  it  is  when  the  angle  of  the  connecting  rod  is  greater. 
Then  again  a  certain  length  of  time  is  required  for  the  reversal  of 
motion  of  the  piston,  during  which  time  the  crank  is  in  motion  but 
the  piston  practically  at  a  standstill.  If  the  valves  are  allowed  to 
remain  open  during  this  period,  the  passage  of  the  gas  in  or  out  of 
the  cylinder  will  be  by  its  own  momentum. 


178  The  Modern  Gasoline  Automobile 

Lead  Gives  Exhaust  Valve. — The  faster  a  motor  turns,  all  other 
things  being  equal,  the  greater  the  amount  of  lead  or  advance  it  is 
necessary  to  give  the  opening  of  the  exhaust  valve.  It  is  self-evident 
truth  that  if  the  speed  of  a  motor  is  doubled,  it  travels  twice  as  many 
degrees  in  the  time  necessary  to  lower  the  pressure.  As  most  designers 
are  cognizant  of  this  fact  the  valves  are  proportioned  accordingly.  It 
is  well  to  consider  in  this  respect  that  the  cam  profile  has  much  to  do 
with  the  manner  in  which  the  valve  is  opened,  that  is,  the  lift  may 
be  abrupt  and  the  gas  allowed  to  escape  in  a  body,  or  the  opening  may 
be  gradual,  the  gas  issuing  from  the  cylinder  in  thin  streams.  An 
analogy  may  be  made  with  the  opening  of  any  bottle  which  contains 
liquid  highly  carbonated.  If  the  cork  is  removed  suddenly  the  gas 
escapes  with  a  loud  pop,  but  on  the  other  hand,  if  the  bottle  is  un- 
corked gradually,  the  gas  escapes  from  the  receptacle  in  thin  streams 
around  the  cork,  and  passage  of  the  gases  to  the  air  is  accomplished 
without  noise.  While  the  second  plan  is  not  harsh,  it  is  slower  than 
the  former,  as  must  be  evident. 

Exhaust  Closing,  Inlet  Opening. — A  point  which  has  been  much 
discussed  by  engineers  is  the  proper  relation  of  the  closing  of  the  ex- 
haust valve  and  the  opening  of  the  inlet.  Theoretically  they  should 
succeed  each  other,  the  exhaust  closing  at  upper  dead  center  and  the 
inlet  opening  immediately  afterward.  The  reason  why  a  certain 
amount  of  lag  is  given  the  exhaust  closing  in  practice  is  that  the 
piston  cannot  drive  the  gases  out  of  the  cylinder  unless  they  are  com- 
pressed to  a  degree  in  excess  of  that  existing  in  the  manifold  or  pas- 
sages, and  while  toward  the  end  of  the  stroke  this  pressure  may  be 
feeble,  it  is  nevertheless  indispensable.  At  the  end  of  the  piston's 
stroke,  as  marked  by  the  upper  dead  center, this  compression  still  exists, 
no  matter  how  little  it  may  be,  so  that  if  the  exhaust  valve  is  closed  and 
the  inlet  opened  immediately  afterward,  the  pressure  which  exists  in 
the  cylinder  may  retard  the  entrance  of  the  fresh  gas  and  a  certain  por- 
tion of  the  inert  gas  may  penetrate  into  the  manifold.  As  the  piston  im- 
mediately begins  to  aspirate  this  may  not  be  serious,  but  as  these  gases 
are  drawn  back  into  the  cylinder  the  fresh  charge  will  be  diluted  and 
weakened  in  value.  If  the  spark  plug  is  in  a  pocket  the  points  may  be 
surrounded  by  this  weak  gas,  and  the  explosion  will  not  be  nearly  as 
energetic  as  when  the  ignition  spark  takes  place  in  pure  mixture. 


The  Modern  Gasoline  Automobile  179 

It  is  a  well-known  fact  that  the  exhaust  valve  should  close  after 
dead  center  and  that  a  certain  amount  of  lag  should  be  given  to  open- 
ing of  the  inlet.  The  lag  given  the  closing  of  the  exhaust  valve  should 
not  be  as  great  as  that  given  the  closing  of  the  inlet  valve.  Assuming 
that  the  excess  pressure  of  the  exhaust  will  equal  the  depression  during 
aspiration,  the  time  necessary  to  complete  the  emptying  of  the  cylinder 
will  be  proportional  to  the  volume  of  the  gas  within  it.  At  the  end 
of  the  suction  stroke  the  volume  of  gas  contained  in  the  cylinder  is 
equal  to  the  cylindrical  volume  plus  the  space  of  the  combustion  cham- 
ber. At  the  end  of  the  exhaust  stroke  the  volume  is  but  that  of  the 
dead  space,  and  from  one-third  to  one-fifth  its  volume  before  compres- 
sion. While  it  is  natural  to  assume  that  this  excess  of  burned  gas  will 
escape  faster  than  the  fresh  gas  will  enter  the  cylinder,  it  will  be  seen 
that  if  the  inlet  valve  were  allowed  to  lag  twenty  degrees,  the  exhaust 
valve  lag  need  not  be  more  than  five  degrees,  providing  that  the  ca- 
pacity of  the  combustion  chamber  was  such  that  the  gases  occupied 
one-quarter  of  their  former  volume. 

It  is  evident  that  no  absolute  rule  can  be  given,  as  back  pressure 
will  vary  with  the  design  of  the  valve  passages,  the  manifolds,  and  the 
construction  of  the  muffler.  The  more  direct  the  opening,  the  sooner 
the  valve  can  be  closed  and  the  better  the  cylinder  cleared.  Ten  de- 
grees represent  an  appreciable  angle  of  the  crank  and  the  time  re- 
quired for  the  crank  to  cover  this  angular  motion  is  not  inconsiderable 
and  an  important  quantity  of  the  exhaust  may  escape,  but  the  piston 
is  still  very  close  to  the  dead  center  after  the  distance  has  been  covered. 

Before  the  inlet  valve  opens  there  should  be  a  certain  depression 
in  the  cylinder,  and  considerable  lag  may  be  allowed  before  the  de- 
pression is  appreciable.  So  far  as  the  volume  of  fresh  gas  introduced 
during  the  admission  stroke  is  concerned,  this  is  determined  by  the 
displacement  of  the  piston  between  the  point  where  the  inlet  valve 
opens  and  the  point  of  closing,  assuming  that  sufficient  gas  has  been 
inspired  so  that  an  equilibrium  of  pressure  has  been  established  be- 
tween the  interior  of  the  cylinder  and  the  outer  air.  The  point  of 
inlet  opening  varies  with  different  motors.  It  would  appear  that  a 
fair  amount  of  lag  would  be  fifteen  degrees  past  top  center  for  the 
inlet  opening,  as  a  certain  depression  will  exist  in  the  cylinder,  assum- 
ing that  the  exhaust  valve  has  closed  five  or  ten  degrees  after  center, 


180  The  Modern  Gasoline  Automobile 

,and  at  the  same  time  the  piston  has  not  gone  down  far  enough  on  its 
stroke  to  materially  decrease  the  amount  of  gas  which  will  be  taken 
into  the  cylinder. 

Closing  the  Inlet  Valve. — As  is  the  case  with  the  other  points  of 
opening  and  closing,  there  is  a  wide  diversity  of  practice  a,s  relates  to 
closing  the  inlet  valve.  Some  of  the  designers  olose  this  exactly  at 
bottom  center,  but  this  practice  cannot  be  commended,  as  there  is  a 
considerable  portion  of  time,  at  least  ten  or  fifteen  degrees  angular 
motion  of  the  crank,  before  the  piston  will  commence  to  travel  any 
extent  on  its  compression  stroke.  The  gases  rushing  into  the  cylinder 
have  considerable  velocity,  and  unless  an  equilibrium  is  obtained 
between  the  pressure  inside  and  that  of  the  atmosphere  outside,  they 
will  continue  to  rush  into  the  cylinder  even  after  the  piston  ceases  to 
exert  any  suction  effect. 

For  this  reason,  if  the  valve  is  closed  exactly  on  center,  a  full 
charge  may  not  be  inspired  into  the  cylinder,  though  if  the  time  of 
closing  is  delayed,  this  momentum  or  inertia  of  the  gas  will  be  enough 
to  insure  that  a  maximum  charge  is  taken  into  the  cylinder.  The 
writer  considers  that  nothing  will  be  gained  if  the  valve  is  allowed  to 
remain  open  longer  than  twenty  degrees,  and  an  analysis  of  practice 
in  this  respect  would  seem  to  confirm  this  opinion.  From  that  point 
in  the  crank  movement  the  piston  travel  increases  and  the  compressive 
effect  is  appreciable,  and  it  would  appear  that  a  considerable  propor- 
tion of  the  charge  might  be  exhausted  into  the  manifold  and  carbu- 
retor if  the  valve  were  allowed  to  remain  open  beyond  a  point  cor- 
responding to  twenty  degrees  angular  movement  of  the  crank. 

Time  of  Ignition. — In  this  country  engineers  unite  in  providing 
a  variable  time  of  ignition,  though  abroad  some  difference  of  opinion 
is  noted  on  this  point.  The  practice  of  advancing  the  time  of  ignition, 
when  affected  electrically,  was  severely  condemned  by  early  makers, 
these  maintaining  that  it  was  necessary  because  of  insufficient  heat 
and  volume  of  the  spark,  and  it  was  thought  that  advancing  ignition 
was  injurious.  The  engineers  of  to-day  appreciate  the  fact  that  the 
heat  of  the  electric  spark,  especially  when  from  a  mechanical  generator 
of  electrical  energy,  is  the  only  means  by  which  we  can  obtain  prac- 
tically instantaneous  explosion,  as  required  by  the  operation  of  motors 
at  high  speeds,  and  for  the  combustion  of  large  volumes  of  gas. 


The  Modern  Gasoline  Automobile  181 

It  is  apparent  that  a  motor  with  a  fixed  point  of  ignition  is 
not  as  desirable,  in  every  way,  as  one  in  which  the  ignition  can 
be  advanced  to  best  meet  different  requirements,  and  the  writer  does 
not  readily  perceive  any  advantage  outside  of  simplicity  of  control  in 
establishing  a  fixed  point  of  ignition.  In  fact,  there  seems  to  be  some 
difference  of  opinion  among  those  designers  who  favor  fixed  ignition, 
and  in  one  case  this  is  located  forty-three  degrees  ahead  of  center,  and 
in  another  motor  the  point  is  fixed  at  twenty  degrees,  so  that  it  may 
be  said  that  this  will  vary  as  much  as  one  hundred  per  cent  in  various 
forms.  This  point  will  vary  with  different  methods  of  ignition,  as 
well  as  the  location  of  the  spark  plug  or  igniter.  The  writer  favors 
a  variable  point  of  ignition,  as  this  offers  advantages  which  cannot  be 
obtained  with  fixed  ignition,  and  enables  one  to  best  gauge  the  require- 
ments of  the  time  of  firing  the  charge  by  conditions  of  operation  from 
time  to  time.  The  range  may  be  as  desired,  varying  from  a  point 
after  center  for  starting  to  one  forty-five  degrees  advanced  for  maxi- 
mum speed.  Then  again,  flexibility  of  control  is  greatly  increased 
when  spark  time  may  be  varied  to  suit  requirements. 

It  is  obvious  by  consideration  of  the  foregoing  that  there  can  be 
no  arbitrary  rules  established  for  timing,  because  of  the  many  condi- 
tions which  determine  the  best  times  for  opening  and  closing  the 
valves.  It  is  customary  to  try  various  settings  when  a  new  motor  is 
designed  until  the  most  satisfactory  points  are  determined,  and  the 
setting  which  will  be  very  suitable  for  one  motor  is  not  always  right 
for  one  of  different  design. 

A  series  of  valve-timing  diagrams  are  presented  at  Fig.  93,  these 
showing  the  timing  employed  on  four  different  engines  of  about  the 
same  size.  In  that  outlined  at  A  the  inlet  valve  begins  to  open  eight 
degrees  after  center  and  closes  exactly  on  the  bottom  center.  The 
exhaust  opens  thirty  degrees  before  bottom  center  and  closes  five 
degrees  after  top  center.  This  motor  employs  large  valves  placed 
in  the  head  and  does  not  need  much  lead  of  the  exhaust  opening. 
In  the  diagram  shown  at  B  the  inlet  valve  has  a  lag  of  fourteen 
degrees  on  the  opening  and  closes  six  degrees  after  bottom  center. 
The  exhaust  valve  opens  forty-one  degrees  before  bottom  center. 
The  timing  method  outlined  at  C  gives  a  greater  lead  to  the  ex- 
haust than  any  of  the  others  shown.  The  exhaust  valve  starting 


182 


The  Modern  Gasoline  Automobile 


to  open  forty-seven  degrees  before  center  and  closing  twelve  degrees 
after  top  center.  The  inlet  valve  begins  to  open  nine  degrees  after 
top  center  and  lags  seventeen  degrees  after  bottom  center.  It  will  be 


Fig.  93. — Diagrams  Showing  Different  Valve  Timing  Methods. 


noticed  that  the  exhaust  valve  is  just  closing  while  the  inlet  is  open- 
ing, the  closing  of  one  member  being  coincident  with  the  opening  of 


The  Modern  Gasoline  Automobile  183 

the  other.  This  is  not  very  often  followed,  because  there  is  danger  of 
the  admixture  of  gases  should  anything  interfere  with  prompt  valve 
action. 

The  diagram  shown  at  D  does  not  differ  very  much  from  that 
shown  at  B,  except  in  the  lag  of  the  inlet  valve.  This  opens  at  thir- 
teen degrees  after  top  center  and  does  not  close  until  twenty-two  de- 
grees after  bottom  center.  The  exhaust  valve  opens  thirty-nine  de- 
grees before  bottom  center  and  closes  ten  degrees  after  top  center.  It 
will  be  seen  that  at  A  there  is  a  lapse  of  three  degrees  between  exhaust 
valve  closing  and  inlet  valve  opening.  At  B  the  lapse  is  two  'degrees. 
At  C  the  timing  arrangement  is  such  that  there  is  no  lapse  between 
exhaust  closing  and  inlet  opening.  Practically  as  soon  as  the  exhaust 
valve  is  closed  fully  the  inlet  valve  has  opened  materially.  At  D  the 
lapse  between  exhaust  valve  closing  and  inlet  opening  is  three  degrees. 
These  methods  of  timing  may  be  considered  representative,  though 
almost  every  designer  follows  his  own  preferences.  Sometimes  con- 
siderable experimenting  is  necessary  before  the  point  is  reached  where 
the  motor  runs  with  the  maximum  power  and  without  noise. 

The  diagram  at  Fig.  94  shows  clearly  the  method  utilized  in  mark- 
ing the  fly  wheel  of  a  typical  four-cylinder  engine  so  that  the  valves 
may  be  properly  timed  without  following  piston  or  crank-shaft  move- 
ment directly.  The  fly  wheel,  which  is  15^4  inches  in  circumference, 
has  been  marked  off  as  indicated.  As  this  is  a  four-cylinder  engine, 
the  marks  on  the  fly  wheel  enable  one  to  time  all  cylinders,  as  one  of 
two  will  fire  when  one  mark  corresponding  to  upper  center  coincides 
with  the  fixed  indicating  device  on  the  center  line  of  the  crank  case. 
The  others  explode  in  turn  when  the  mark  indicating  the  lower  center 
registers  with  the  trammel  point,  as  the  little  indicating  device  on  the 
crank  case  is  called.  When  the  diameter  of  a  fly  wheel  is  15^4  inches, 
'<?.()(> 2  inches  measured  from  one  of  the  center  lines  indicate  the  crank- 
pin  travel  of  fifteen  degrees.  The  lag  of  inlet  closing  which  in  this 
motor  is  thirty-three  degrees  is  represented  by  a  distance  of  4.536 
inches  on  the  circumference  of  the  fly  wheel.  The  exhaust  valve  lead 
which  is  fifty-three  degrees  and  thirty  minutes  is  determined  by  meas- 
uring 7.353  inches  ahead  of  the  center  lines.  The  point  where  the 
exhaust  valve  closes  which  is  twelve  degrees  after  center  is  represented 
by  a  distance  of  1.649  inches  on  the  fly  wheel.  It  will  be  noted  that  in 


184 


The  Modern  Gasoline  Automobile 


this  case  there  is  a  lapse  of  three  degrees  between  the  exhaust  closing 
and  the  inlet  opening.  The  exhaust  valve  is  kept  open  considerably 
longer  than  is  usually  the  case,  as  it  lags  thirty-three  degrees  after  the 
piston  is  started  to  go  up  on  its  compression  stroke.  The  exhaust 


Trammel 


Inlet  Opens  15°=  2. 062" 
Late  on  Circumference. 
Inlet  Closes  33 °=4. 536" 
Late  on  Circumference. 
Exhaust  Opens  53°30'=7.353 
Early  on  Circumference. 
Exhaust  Closes  12°=  1.649 
Late  on  Circumference. 

Motor  Fires  1-3-4-2 


HUDSON 


Fig.  94. — Diagram  Showing  Method  of  Marking  Fly-wheel  Circumference  to 
Obtain  Proper  Timing  of  Typical  Four-Cylinder  Motor. 

valve  opens  much,  earlier,  i.  e.,  it  is  given  a  greater  lead  than  an  analy- 
sis of  common  practice  shows  to  he  desirable.  The  exhaust  valve  is 
opened  considerably  longer  than  is  usually  the  case,  as  the  average 
lead  given  to  exhaust  is  about  forty  degrees. 

In  timing  a  motor  from  the  marks  on  the  fly-wheel  rim  it  is  neces- 
sary to  regulate  the  valves  of  but  one  cylinder  at  a  time.  Assuming 
that  the  fly  wheel  is  revolving 'in  the  direction  of  the  arrow  and  that 
the  firing  order  of  the  cylinders  is  1-3-4-2  the  operation  of  timing 
would  be  carried  on  as  follows :  The  fly  wheel  would  be  revolved  until 


The  Modern  Gasoline  Automobile  185 

the  line  marked  "  Exhaust  opens  1  and  4  "  registered  with  the  trammel 
on  the  motor  bed.  At  this  point  the  exhaust  valve  of  either  cylinder 
No.  1  or  No.  4  should  begin  to  open.  This  can  be  easily  determined 
by  noting  which  of  these  cylinders  holds  the  compressed  charge  ready 
for  ignition  when  the  fly  wheel  is  in  the  position  shown  in  drawing. 
Assuming  that  the  spark  has  occurred  in  cylinder  No.  1,  then  when 
the  fly  wheel  is  turned  from  the  position  shown  in  the  sketch  to  that 
in  which  the  line  marked  "  Exhaust  opens  1  to  4  "  coincides  with  the 
trammel  point,  the  valve  plunger  under  the  exhaust  valve  of  cylinder 
No.  1  should  be  adjusted  in  such  a  way  that  there  is  no  clearance 
between  it  and  the  valve  stem.  Further  movement  of  the  wheel  in 
the  same  direction  should  produce  a  lift  of  the  exhaust  valve.  The 
fly  wheel  is  turned  about  two  hundred  and  forty-five  degrees  or  about 
three-quarters  of  a  revolution ;  then  the  line  marked  "  Exhaust  closes 
1  and  4  "  will  register  with  the  trammel  point.  At  this  period  the 
valve  plunger  and  the  valve  stem  should  separate  and  a  certain  amount 
of  clearance  obtained  between  them.  The  next  cylinder  to  time  would 
be  No.  3.  The  fly  wheel  is  rotated  until  mark  "  Exhaust  opens  2  and 
3  "  comes  in  line  with  the  trammel.  At  this  point  the  exhaust  valve  of 
cylinder  No.  3  should  be  just  about  opening.  The  closing  is  deter- 
mined by  rotating  the  fly  wheel  until  the  line  "  Exhaust  closes  2  and 
3  "  comes  under  the  trammel. 

This  operation  is  carried  on  with  all  the  cylinders,  it  being  well  to 
remember  that  but  one  cylinder  is  working  at  a  time  and  that  a  half 
revolution  of  the  fly  wheel  corresponds  to  a  full  working  stroke  of  all 
the  cylinders,  and  that  while  one  is  exhausting,  the  others  are  respect- 
ively taking  in  a  new  charge,  compressing  and  exploding.  For  in- 
stance, if  cylinder  No.  1  has  just  completed  its  power  stroke  the 
piston  in  cylinder  No.  3  has  reached  the  point  where  the  gas  may  be 
ignited  to  advantage.  The  piston  of  cylinder  No.  4,  which  is  next  to 
fire,  is  at  the  bottom  of  its  stroke  and  will  have  inspired  a  charge,  while 
cylinder  No.  2,  which  is  the  last  to  fire,  will  have  just  finished  expelling 
a  charge  of  burned  gas,  and  will  be  starting  the  intake  stroke. 


CHAPTER  IV 

Considering  Pistons,  Piston  Rings,  Connecting  Rods,  Crank  Shafts,  the  Fly 
Wheel,  and  Engine  Base  Construction — Typical  Two-  and  Four-Cycle 
Power  Plants  Described. 

Constructional  Details  of  Pistons. — The  piston  is  one  of  the  most 
important  parts  of  the  gasoline  motor  inasmuch  as  it  is  the  recipro- 
cating member  that  receives  the  impact  of  the  explosion  and  which 
transforms  the  power  obtained  by  the  combustion  of  gas  to  mechan- 
ical motion  by  means  of  the  connecting  rod  to  which  it  is  attached. 
The  piston  is  one  of  the  simplest  elements  of  the  motor,  and  it  is  one 
component  which  does  not  vary  much  in  form  in  different  types  of 
motors.  The  piston  is  a  cylindrical  member  provided  with  a  series  of 
grooves  in  which  packing  rings  are  placed  on  the  outside  and  two 
bosses  which  serve  to  hold  the  wrist  pin  in  its  interior.  It  is  usually 
made  of  cast  iron,  though  in  some  motors  where  extreme  lightness  is 
desired,  such  as  those  used  for  aeronautic  work,  it  may  be  made  of 
steel.  The  use  of  the  more  resisting  material  enables  the  engineer  to 
use  lighter  sections  where  it  is  important  that  the  weight  of  this  mem- 
ber be  kept  as  low  as  possible  consistent  with  strength. 

A  number  of  piston  types  are  shown  at  Fig.  95.  That  at  A  has 
a  round  top  and  is  provided  with  four  split  packing  rings  and  two 
oil  grooves.  A  piston  of  this  type  is  generally  employed  in  motors 
where  the  combustion  chamber  is  large  and  where  it  is  desired  to 
obtain  a  higher  degree  of  compression  than  would  be  possible  with  a 
flat  top  piston.  This  construction  is  also  stronger  because  of  the 
arched  piston  top.  The  most  common  form  of  piston  is  that  shown 
at  B,  and  it  differs  from  that  previously  described  only  in  that  it  has 
a  flat  top.  The  piston  outlined  in  section  at  C  is  a  type  used  on  some 
of  the  sleeve-valve  motors  of  the  Knight  pattern,  and  has  a  concave 
head  instead  of  the  convex  form  shown  at  A.  The  design  shown  at 
D  in  side  and  plan  views  is  the  conventional  form  employed  in  two- 
cycle  engines.  The  deflector  plate  on  the  top  of  the  cylinder  is  cast 

186 


The  Modern  Gasoline  Automobile 


187 


integral  and  is  utilized  to  prevent  the  incoming  fresh  gases  from  flow- 
ing directly  over  the  piston  top  and  out  of  the  exhaust  port  which  is 
usually  opposite  the  inlet  opening.  On  those  types  of  two-cycle  en- 
gines where  a  two-diameter  cylinder  is  employed,  the  piston  shown  at 
E  is  used.  This  is  known  as  a  "  differential  piston/'  and  has  an  en- 
larged portion  at  its  lower  end  which  fits  the  pumping  cylinder.  The 


Side  View 


Fig.  95. — Forms  of  Pistons  Commonly  Employed  in  Gasoline  Engines.  A — 
Dome  Head  Piston  with  Three  Packing  Rings.  B — Flat  Top  Form  Almost 
Universally  Used.  C — Concave  Piston  Utilized  in  Knight  Motors  and  Some 
Having  Overhead  Valves.  D — Two-Cycle  Engine  Member  with  Deflector 
Plate  Cast  Integrally.  E — Differential  of  Two-Diameter  Piston  Used  in 
Some  Engines  Operating  on  Two-Cycle  Principle. 

usual  form  of  deflector  plate  is  provided  at  the  top  of  the  piston  and 
one  may  consider  it  as  two  pistons  in  one. 

One  of  the  important  conditions  in  piston  design  is  the  method  of 
securing  the  wrist  pin  which  is  used  to  connect  the  piston  to  the  upper 
end  of  the  connecting  rod.  Various  methods  have  been  devised  to 
keep  the  pin  in  place,  the  most  common  of  these  being  shown  at  Fig. 


188  The  Modern  Gasoline  Automobile 

96.  The  wrist  pin  should  be  retained  by  some  positive  means  whicl 
is  not  liable  to  become  loose  under  the  vibratory  stresses  which  obtain 
at  this  point.  If  the  wrist  pin  was  free  to  move  it  would  work  out  oJ 
the  bosses  enough  so  that  the  end  would  bear  against  the  cylinder  wall. 
As  it  is  usually  made  of  steel,  which  is  a  harder  material  than  cast 
iron  used  in  cylinder  construction,  the  rubbing  action  would  tend  to 
cut  a  groove  in  the  cylinder  wall  which  would  make  for  loss  of  power 
because  it  would  permit  escape  of  gas.  The  wrist  pin  member  is  a 
simple  cylindrical  element  that  fits  the  bosses  closely,  and  it  may  be 
either  hollow  or  solid  stock. 

The  method  of  retention  shown  at  A  is  the  simplest  and  consists 
of  a  set  screw  having  a  projecting  portion  passing  into  the  wrist  pin 
and  holding  it  in  place.  The  screw  is  kept  from  turning  or  loosening 
by  means  of  a  check  nut.  The  method  outlined  at  B  is  similar  to  that 
shown  at  A,  except  that  the  wrist  pin  is  solid  and  the  point  of  the 
set  screw  engages  an  annular  groove  turned  in  the  pin  for  its  recep- 
tion. A  very  positive  method  is  shown  at  C.  Here  the  retention 
screws  pass  into  the  wrist  pin  and  are  then  locked  by  a  piece  of  steel 
wire  which  passes  through  suitable  holes  in  the  ends.  The  method 
outlined  at  D  is  sometimes  employed,  and  it  varies  from  that  shown 
at  C  only  in  that  the  locking  wire,  which  is  made  of  spring  steel,  is 
passed  through  the  heads  of  the  locking  screws.  Some  designers  ma- 
chine a  large  groove  around  the  piston  at  such  a  point  that  when  the 
wrist  pin  is  put  in  place  a  large  packing  ring  may  be  sprung  in  the 
groove  and  hold  the  wrist  pin  in  place. 

The  system  shown  at  F  is  not  so  widely  used  as  the  simpler  meth- 
ods, because  it  is  more  costly  and  does  not  offer  any  greater  security 
when  the  parts  are  new  than  the  simple  lock  shown  at  A.  In  this  a 
hollow  wrist  pin. is  used,  having  a  tapered  thread  cut  at  each  end.  The 
wrist  pin  is  slotted  at  three  or  four  points,  for  a  distance  equal  to  the 
length  of  the  boss,  and  when  taper  expansion  plugs  are  screwed  in 
place  the  ends  of  the  wrist  pin  are  expanded  against  the  bosses.  This 
method  has  the  advantage  of  providing  a  certain  degree  of  adjustment 
if  the  wrist  pin  should  loosen  up  after  it  had  been  in  use  for  some  time. 
The  taper  plugs  would  be  screwed  in  deeper  and  the  ends  of  the  wrist 
pin  expanded  proportionately  to  take  up  the  loss  motion.  The  method 
shown  at  G  is  an  ingenious  one,  One  of  the  piston  bosses  is  provided 


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190  The  Modern  Gasoline  Automobile 

with  a  projection  which  is  drilled  out  to  receive  a  plunger.  The  wrist 
pin  is  provided  with  a  hole  of  sufficient  size  to  receive  the  plunger, 
which  is  kept  in  place  hy  means  of  a  spring  in  back  of  it.  This  makes 
a 'very  positive  lock  and  one  that  can  be  easily  loosened  when  it  is 
desired  to  remove  the  wrist  pin.  To  unlock,,  a  piece  of  fine  rod  is 
thrust  into  the  hole  at  the  bottom  of  the  boss  and  pushes  the  plunger 
back  against  the  spring  until  the  wrist  pin  can  be  pushed  out  of  the 
piston. 

Some  engineers  think  it  advisable  to  oscillate  the  wrist  pin  in 
the  piston  bosses,  instead  of  in  the  connecting  rod  small  end.  It  is 
argued  that  this  construction  gives  more  bearing  surface  at  the  wrist 
pin  and  also  provides  for  more  strength  because  of.  the  longer  bosses 
that  can  be  used.  When  this  system  is  followed  the  piston  pin  is  held 
in  place  by  locking  it  to  the  connecting  rod  by  some  means.  At  H 
the  simplest  method  is  outlined.  This  consisted  of  driving  a  taper 
pin  through  both  rod  and  wrist  pin  and  then  preventing  it  from  back- 
ing out  by  putting  a  split  cotter  through  the  small  end  of  the  tapered 
locking  pin.  Another  method,  which  is  depicted  at  I,  consists  of 
clamping  the  wrist  pin  by  means  of  a  suitable  bolt  which  brings  the 
slit  connecting  rod  end  together  as  shown. 

Piston  Ring  Construction. — As  all  pistons  must  be  free  to  move  up 
and  down  in  the  cylinder  with  minimum  friction,  they  must  be  less 
in  diameter  than  the  bore  of  the  cylinder.  The  amount  of  freedom  or 
clearance  provided  varies  with  the  construction  of  the  engine,  but  it 
is  usual  to  provide  from  .005  to  .010  of  an  inch  to  compensate  for 
the  expansion  of  the  piston  due  to  heat  and  also  to  leave  sufficient 
clearance  for  the  introduction  of  lubricant  between  the  working  sur- 
faces. Obviously,  if  the  piston  were  not  provided  with  packing  rings, 
this  amount  of  clearance  would  enable  a  portion  of  the  gases  evolved 
when  the  charge  is  exploded  to  escape  by  it  into  the  engine  crank  case. 
The  packing  members  or  piston  rings,  as  they  are  called,  are  split  rings 
of  cast  iron,  which  are  sprung  into  suitable  grooves  machined  on  the 
exterior  of  the  piston,  three  or  four  of  these  being  the  usual  number 
supplied^  These  have  sufficient  elasticity  so  that  they  bear  tightly 
against  the  cylinder  wall  and  thus  make  a  gas-tight  joint.  Owing  to 
the  limited  amount  of  surface  in  contact  with  the  cylinder  wall  and  the 
elasticity  of  the  split  rings  the  amount  of  friction  resulting  from  the 


The  Modern  Gasoline  Automobile 


191 


contact  of  properly  fitted  rings  and  the  cylinder  is  not  of  enough  mo- 
merit  to  cause  any  damage  and  piston  is  free  to  slide  up  and  down  in 
the  cylinder  bore. 

These  rings  are  made  in  two  forms,  as  outlined  at  Pig.  97.  The 
design  shown  at  A  is  termed  a  "  concentric  ring/'  because  the  inner 
circle  is  concentric  with  the  outer  one  and  the  ring  is  of  uniform 


D 


Fig.  97. — Types  of  Piston  Rings  and  Ring  Joints.  .  A— Concentric  Ring.  B— Ec- 
centrically Machined  Form.  C — Lap  Joint  Ring.  D — Butt  Joint,  Seldom 
Used.  E — Diagonal  Cut  Member,  a  Popular  Form. 

thickness  at  all  points.  The  ring  shown  at  B  is  called  an  "  eccentric 
ring,"  and  it  is  thicker  at  one  part  than  the  other.  It  has  theoretical 
advantages  in  that  it  will  make  a  tighter  joint  than  tHe  other  form, 
as  it  is  claimed  its  expansion  due  to  heat  is  more  uniform.  The  piston 
rings  must  be  split  in  order  that  they  may  be  sprung  in  place  in  the 
grooves,  and  also  to  insure  that  they  will  have  sufficient  elasticity  to 
take  the  form  of  the  cylinder  at  the  different  points  in  their  travel.  If 
the  cylinder  bore  varies  by  small  amounts  the  rings  will  spring  out  at 
the  points  where  the  bore  is  larger  than  standard,  and  spring  in  at 
those  portions  where  it  is  smaller  than  standard. 

It  is  important  that  the  joint  should  be  as  nearly  gas-tight  as  pos- 
sible, because  if  it  were  not  a  portion  of  the  gases  would  escape  through 
the  slots  in  the  piston  rings.  The  joint  shown  at  C  is  termed  a  "  lap 
joint,"  because  the  ends  of  the  ring  are  cut  in  such  a  manner  that 
they  overlap.  This  is  the  approved  joint.  The  butt  joint  shown  at 
D  is  seldom  used  and  is  a  very  poor  form,  the  only  advantage  being 
its  cheapness.  The  diagonal  cut  shown  at  E  is  a  compromise  between 
the  very  good  form  shown  at  C  and  the  poor  joint  depicted  at  D.  It 


192 


The  Modern  Gasoline  Automobile 


is  also  widely  used,  though  most  constructors  prefer  the  lap  joint, 
because  it  does  not  permit  the  leakage  of  gas  as  much  as  the  other  two 
types. 

The  illustration  at  Fig.  98  shows  a  typical  flat  top  piston,  provided 
with  diagonal  cut  concentric  packing  rings.     One  of  these  members  is 


Fig.  98. — Showing  Flat-Top  Piston  Provided  with  Four  Concentric  Rings,  One 
of  the  Packing  Members  and  the  Wrist  Pin  with  its  Bushing. 

shown  on  top  of  the  piston  and  the  wrist  pin  and  the  bushing  which 
fits  it  and  which  is  forced  into  the  small  end  of  the  connecting  rod 
are  placed  at  one  side.  In  some  cases  the  piston  rings  are  pinned  in 
place  in  their  grooves  so  that  they  cannot  move  around  until  they  are 
all  in  such  a  position  that  the  slots  will  come  in  line.  In  others,  it  is 
believed  that  they  are  left  free  to  turn  that  they  will  wear  in  place 


The  Modern  Gasoline  Automobile  193 

and  conform  to  the  bore  of  the  cylinder  better  than  if  they  are  kept 
from  turning.  When  the  rings  are  pinned  they  usually  have  the  diag- 
onal cut,  while  those  that  are  left  free  are  usually  provided  with  the 
lap  joint. 

Connecting  Rod  Forms. — The  connecting  rod  is  the  simple  member 
that  joins  the  piston  to  the  crank  shaft  and  which  transmits  the 


Fig.  99.— Typical  Connecting  Rod  and  its  Wrist  Pin.     Lower  Bearing  Cap  Held 
by  Four  Bolts.     White  Metal  Boxes  in  Cast  Bronze  Rod. 

power  imparted  to  the  piston  by  the  explosion  so  that  it  may  be  use- 
fully applied.  It  transforms  the  reciprocating  movement  of  the  piston 
to  a  rotary  motion  at  the  crank  shaft.  A  typical  connecting  rod  and 
its  wrist  pin  are  shown  at  Fig.  99.  It  will  be  seen  that  it  has  two 
bearings,  one  at  either  end.  The  small  end  is  bored  out  to  receive 
the  wrist  pin  which  joins  it  to  the  piston,  while  the  large  end  has 
a  hole  of  sufficient  size  to  go  on  the  crank  pin.  The  connecting  rod 
is  usually  a  steel  forging,  though  it  is  sometimes  made  a  steel  or  high 
tensile  strength  bronze  casting.  In  all  cases  it  is  desirable  to  have 
softer  metals  than  the  crank  shaft  and  wrist  pin  at  the  bearing  point, 
and  for  this  reason  the  connecting  rod  is  usually  provided  with  bush- 
ings of  anti-friction  or  white  metal  at  the  lower  end,  and  bronze  at 
the  upper.  The  upper  end  of  the  connecting  rod  may  be  one  piece, 
.because  the  wrist  pin  can  be  introduced  after  it  is  in  place  between 
the  bosses  of  the  piston.  The  lower  bearing  must  be  made  in  two 
parts  in  most  cases,  because  the  crank  shaft  cannot  be  passed  through 
the  bearing  owing  to  its  irregular  form. 


194  The  Modern  Gasoline  Automobile 

Some  of  the  various  designs  of  connecting  rods  that  have  been 
used  are  shown  at  Fig.  100.  That  at  A  is  a  simple  form  often  em- 
ployed in  single-cylinder  motors.,  having  built-up  crank  shafts.  Both 
ends  of  the  connecting  rod  are  bushed  with  a  one-piece  bearing,  as  it 
can  be  assembled  in  place  before  the  crank-shaft  assembly  is  built  up. 
A  built-up  crank  shaft  such  as  this  type  of  connecting  rod  would  be 
used  with  is  shown  at  Fig.  106.  The  pattern  shown  at  B  is  one  that 
has  been  used  to  some  extent  on  heavy  work,  and  is  known  as  the 
"marine  type."  It  is  made  in  three  pieces,  the  main  portion  being 
a  steel  forging  having  a  flanged  lower  end  to  which  the  bronze  boxes 
are  secured  by  bolts.  The  modified  marine  type  depicted  at  C  is  the 
form  that  has  received  the  widest  application  in  automobile  construc- 
tion. It  consists  of  two  pieces,  the  main  member  being  a  steel  drop 
forging  having  the  wrist-pin  bearing  and  the  upper  crank-pin  bearing 
formed  integral,  while  the  lower  crank-pin  bearing  member  is  a  sepa- 
rate forging  secured  to  the  connecting  rod  by  bolts.  In  this  construction 
bushings  of  anti-friction  metal  are  used  at  the  lower  end,  and  a  bronze 
bushing  is  forced  into  the  upper-  or  wrist-pin  end.  The  rod  shown 
at  D  has  also  been  widely  used.  It  is  similar  in  construction  to  the 
form  shown  at  C,  except  that  the  upper  end  is  split  in  order  to  permit 
of  a  degree  of  adjustment  of  the  wrist-pin  bushing,  and  the  lower 
bearing  cap  is  a  hinged  member  which  is  retained  by  one  bolt  instead 
of  two.  When  it  is  desired  to  assemble  it  on  the  crank  shaft  the  lower 
cap  is  swung  to  one  side  and  brought  back  into  place  when  the  con- 
necting rod  has  been  properly  located.  Sometimes  the  lower  bearing 
member  is  split  diagonally  instead  of  horizontally,  such  a  construction 
being  outlined  at  E. 

In  a  number  of  instances,  instead  of  plain  bushed  bearings  anti- 
friction forms  using  ball  or  rollers  have  been  used  at  the  lower  end. 
A  ball-bearing  connecting  rod  is  shown  at  F.     The  big  end  may  bo 
made  in  one  piece,  because  if  it  is  possible  to  get  the  ball  bearing 
on  the  crank   pins   it  will  be   easy   to   put  the   connecting   rod   in 
place.      Ball  bearings   are   not  used   very   often   on   connecting   rod 
big  enSs  because  of  difficulty  of  installation,  though  when  applied 
properly  they  give  satisfactory  service  and  reduce  friction  to  a  mini-  : 
mum.     One  of  the  advantages  of  the  ball  bearing  is  that  it  requires  fj 
no  adjustment,  whereas  the  plain  bushings  depicted  in  the  other  con- 


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The  Modern  Gasoline  Automobile 


necting  rods  must  be  taken  up  from  time  to  time  to  compensate  for 


wear. 


This  can  be  done  in  forms  shown  at  B,  C,  D,  and  E  by  bringing 
the  lower  bearing  caps  closer  to  the  upper  one  and  scraping  out  the 


Fig.  101. — Crank  Shaft,  Piston  and  Connecting  Rod  Assembly  Used  in  Reo 

Motors. 

brasses  to  fit  the  shaft.  A  number  of  liners  or  shims  of  thin  brass  or 
copper  stock  varying  from  .002  inch  to  .005  inch  are  sometimes  inter- 
posed between  the  halves  of  the  bearings  when  it  is  first  fitted  to  the 
crank  pin.  .As  the  brasses  wear  the  shims  may  be  removed  and  the 
portions  of  the  bearings  brought  close  enough  together  to  take  up  anv 
lost  motion  that  may  exist. 

The  various -structural  shapes  in  which  connecting  rods  are  formed 
are  shown  in  section  at  G.  Of  these  the  I  section  is  most  common, 
because  it  is  strong  and  a  very  easy  shape  to  form  by  the  drop-forging 
process.  Where  extreme  lightness  is  desired,  as  in  small  high-speed 
motors  used  for  cycle  propulsion,  the  section  shown  at  the  extreme 
left  is  often  used.  If  the  rod  is  a  cast  member  the  cross,  hollow  cylin- 
der, or  U  sections  are  sometimes  used.  If  the  sections  shown  at  the 
right  are  employed,  advantage  is  often  taken  of  the  opportunity  for 
passing  lubricant  through  the  center  of  the  hollow  round  section  on 


The  Modern  Gasoline  Automobile  197 

vertical  motors  or  at  the  bottom  of  the  U  section,  which  would  be  used 
on  a  horizontal  cylinder  power  plant. 

Cam-Shaft  Forms. — Piston  and  connecting  rod  types  having  been 
described,  the  next  component  of  importance  to  receive  attention 
should  be  the  crank  shaft.  These  vary  in  form  according  to  the  de- 
signs of  the  motor  and  number  of  cylinders  employed.  A  typical 
crank  shaft,  piston,  and  connecting  rod  assembly  which  forms  part  of 
the  Eeo  motor  is  shown  at  Fig.  101,  and  the  parts  are  so  clearly  shown 
that  no  description  is  necessary. 

Before  going  extensively  into  the  subject  of  crank-shaft  construc- 
tion it  will  be  well  to  consider  cam-shaft  design,  which  is  properly  a. 
part  of  the  valve  system  and  which  should  be  considered  in  connection 


Fig.  102.— Some  of  the  Components  of  Corbin  "  40  "  Motor.  A — Piston  and  Con- 
necting Rod  Assembly.  B — Inlet  and  Exhaust  Cam  Shafts.  C — Twin- 
Cylinder  Casting. 

with  the  other  elements  which  have  to  do  directly  with  cylinder  con- 
struction. Cam  shafts  are  usually  simple  members  carried  at  the  base 
of  the  cylinder  in  the  engine  case  by  suitable  bearings  and  having  the 
cams  employed  to  lift  the  valves  attached  at  intervals.  A  typical  cam- 
shaft design  is  shown  at  Fig.  102  in  connection  with  one  of  the  twin- 
cylinder  castings  and  the  piston  and  connecting  rod  assembly  of  the 


198  The  Modern  Gasoline  Automobile 

Corbin  "  40  "  motor.  Two  main  methods  of  cam-shaft  construction 
are  followed — that  in  which  the  cams  are  separate  members,  keyed 
and  pinned  to  the  shaft,  and  the  other  where  the  cams  are  formed 
integral. 

The  cam  shafts  shown  at  Fig.  102  are  of  the  former  type,  as  the 
cams  are  machined  separately  and  held  in  place  by  means  of  keys  and 


t 


Fig.  103. — Typical  Cam  Shaft  with  Valve  Lifting  Cams  and  Gears  to  Operate 
Auxiliary  Devices  Forged  Integrally. 

taper  pins.  The  small  gears  used  to  drive  some  of  the  accessory  mech- 
anism, such  as  the  oil  pump,  timer,  etc.,  are  also  separately  formed 
and  pinned  to  the  cam  shaft.  At  Fig.  103  the  other  method  of  cam- 
shaft construction  is  outlined.  In  this  case  not  only  the  cams  but  also 
the  gears  used  in  driving  the  auxiliary  shafts  are  forged  integral. 
This  is  a  more  expensive  construction  than  that  shown  at  Fig.  102, 
because  of  the  high  initial  cost  of  forging  dies  as  well  as  the  greater 
expense  of  machining.  It  has  the  advantage  over  the  other  form  in 
which  the  cams  are  keyed  in  place  in  that  it  is  stronger,  and  as  the 
cams  are  a  part  of  the  shaft  they  can  never  become  loose,  as  might  be 
possible  where  they  are  separately  formed  and  assembled  on  a  simple 
shaft.  As  an  example  of  an  auxiliary  shaft  carried  at  the  side  of  the 
motor  and  driven  from  the  cam  shaft  the  assembly  at  Fig.  104  is 
given.  This  is  driven  from  one  of  the  small  gears  shown  at  Fig.  103 
and  carries  the  ignition  timer  at  the  upper  end  and  drives  the  oil 
pump  through  a  spring  coupling  at  its  lower  end. 

Crank-shaft  Types  Outlined, — The  importance  of  the  crank  shaft 
has  been  previously  considered,  and  some  of  its  forms  have  been  shown 
in  views  of  the  motors  presented  in  earlier  portions  of  this  work.  The 
crank  shaft  is  one  of  the  parts  subjected  to  the  greatest  strain  and 
extreme  care  is  needed  in  its  construction  and  design,  because  prac- 


The  Modern  Gasoline  Automobile 


199 


tically  the  entire  duty  of  trans- 
mitting the  power  generated  by 
the  motor  to  the  gearset  de- 
volves upon  it.  Crank  shafts  are 
usually  made  of  high  tensile 
strength  steel  of  special  composi- 
tion. They  may  be  made  in  four 
ways,  the  most  common  being 
from  a  drop  or  machine  forg- 
ing which  is  formed  approxi- 
mately to  the  shape  of  the  fin- 
ished shaft  and  in  rare  instances 
they  may  be  steel  castings. 
Sometimes  they  are  made  from 
machine  forgings,  where  con- 
siderably more  machine  work 
is  necessary  than  would  be  the 
case  where  the  shaft  is  formed 
between  dies.  Some  engineers 
favor  blocking  the  shaft  out  of 
a  solid  slab  of  metal  and  then 
machining  this  rough  blank  to 
form.  In  some  single-cylinder 
motors  of  the  enclosed  fly-wheel 
type  the  crank  shaft  and  fly 
wheel  are  built  up  as  a  unit. 

The  form  of  the  shaft  de- 
pends on  the  number  of  cylin- 
ders and  the  form  has  material 
influence  on  the  method  of  con- 
struction. For  instance,  a  one-, 
two-  or  four-cylinder  crank  shaft 
could  be  made  by  either  of  the 
methods  outlined.  On  the  other 
hand,  a  three-  or  six-cylinder 
shaft  is  best  made  by  the  ma- 
chine forging  process,  because 


Fig.  104.— Auxiliary  Shaft  Used  in  Con- 
nection with  Cam  Shaft  Driven  from  a 
Spiral  Gear  Turns  Timer  and  Oil  Pump. 


200 


The  Modern  Gasoline  Automobile 


if  drop  forged  or  cut  from  the  blank  it  will  have  to  be  heated  and  the 
crank  throws  bent  around  so  that  the  pins  will  lie  in 'three  planes  one 
hundred  and  twenty  degrees  apart,  while  the  other  types  described 
need  no  further  attention,  as  the  crank  pins  lie  in  planes  one  hundred 


Fig.  105. — Showing  Method  of  Making  Crank  Shaft.  A — The  Rough  Steel 
Forging  Before  Machining.  B — The  Finished  Six-Throw,  Seven-Bearing 
Crank  Shaft. 

and  eighty  degrees  apart.  This  can  be  better  understood  by  referring 
to  Fig.  105,  which  shows  a. six-cylinder  shaft  in  the  rough  and  finished 
stages.  At  A  the  appearance  of  the  machine  forging  before  any  of 
the  material  is  removed  is  shown,  while  at  B  the  appearance  of  the 
finished  crank  shaft  is  clearly  depicted.  The  built-up  crank  shaft  is 
seldom  used  on  multiple-cylinder  motors,  except  in  some  cases  where 
the  crank  shafts  revolve  on  ball  bearings  and  the  connecting  rods  are 
provided  with  this  form  as  well. 

A  typical  single-cylinder  high-speed  motor  is  shown  at  Fig.  106, 
this  being  the  De  Dion-Bouton,  a  power  plant  which  has  been  quite 
popular  in  France  in  the  past  for  "  voiturette  "  or  small  car  use.  In 
this  design  the  flywheels  are  enclosed  in  the  crank  case  and  the  crank 
shaft  is  a  built-up  construction  formed  of  five  pieces.  The  two  halves 
of  the  crank  shaft  fit  into  taper  holes  in  the  fly  wheels  and  are  held 
securely  in  place  by  means  of  keys  and  clamping  nuts.  The  crank  pin 
is  similarly  retained.  Brief  study  of  the  illustration  will  show  this 
method  of' 'construction  very  clearly.  It  should  be  stated  that  this  is 
seldom  used  on  automobile  motors  but  that  it  is  very  common  con- 
struction in  motorcycle  power  plants. 


The  Modern  Gasoline  Automobile 


201 


Flywheel 


Fig.  106. — Defining  Built-up  Crank- shaft  Construction  Sometimes  Used  in  Small 

Motors. 


202 


The  Modern  Gasoline  Automobile 


Crank-shaft  form  will  vary  with  a  number  of  cylinders  and  it  is 
possible  to  use  a  number  of  different  arrangements  of  crank  pins  and 
bearings  for  the  same  number  of  cylinders.  The  simplest  form  of 


Fig.  107. — Showing  Form  of  Crank  Shaft  for  Twin-Cylinder  Opposed  Power 

Plant. 

crank  shaft  is  that  used  on  a  one-cylinder  motor,  as  it  would  consist 
of  but  one  crank  pin,  two  webs,  and  the  crank  shaft.    As  the  number 


Fig.  108. — Two  Forms  of  Four-Cylinder  Crank  Shaft.  A — Five-Bearing  Type 
with  Fly-wheel  Fastening  Key  at  Front  End.  B— Three-Bearing  Type  with 
Flange  for  Securing  Fly-wheel  Formed  Integral. 

of  cylinders  increase,  as  a  general  rule  more  crank  pins  are  used.  The 
crank  shaft  that  would  be  used  on  a  two-cylinder  opposed  motor  is 
shown  at  Fig.  107.  This  has  two  throws  and  the  crank  pins  are 


The  Modern  Gasoline  Automobile 


203 


spaced  180  degrees  apart.  The  bearings  are  exceptionally  long  and  a 
flange  is  forged  integral  at  the  rear  end  for  fly-wheel  retention.  Four- 
cylinder  crank  shafts  may  have  two,  three  or  five  main  bearings  and 
three  or  four  crank  pins.  In  some  forms  of  two-bearing  crank  shafts, 
such  as  used  when  four  cylinders  are  cast  in  a  block,  or  unit  casting, 
two  of  the  pistons  are  attached  to  one  common  crank  pin,  so  that  in 
reality  the  crank  shaft  has  but  three  crank  pins.  Such  a  form  is 
shown  at  Fig.  112,  which  depicts  a  four-cylinder  two-bearing  crank 
shaft  used  on  Chalmers'  motors. 

When  the  cylinders  are  cast  individually  five-bearing  crank  shafts 
are  the  rule.     One  of  these,  which  is  used  on  Maxwell  engines,  is  shown 


Fig.  109.— Representative  Three-Bearing  Crank  Shafts.  A— For  Use  with 
Cylinders  Cast  in  Pairs.  B— Used  with  Individually  Cast  Cylinders.  Note 
Round  Section  Portions  Connecting  Ends  to  Center  Crank  Throws. 

at  Fig.  108,  A.  The  three-bearing  type  shown  at  Fig.  108,  B,  is  used 
when  the  cylinders  are  cast  in  pairs.  Two  other  three-bearing  shafts 
.used  in  four-cylinder  motors  are  shown  at  Fig.  109.  That  at  A  forms 
part  of  the  E.  M.  F.  engine,  which  has  the  cylinders  cast  in  pairs, 
while  the  three-bearing  four-throw  type,  shown  at  B,  is  used  in  the 
Rambler  four-cylinder  engine,  which  has  individually  cast  cylinders. 
Six-cylinder  crank  shafts  usually  have  four  or  seven  main  bearings 
depending  upon  the  disposition  of  the  crank  pins  and  arrangement  of 
cylinders.  At  Fig.  110  the  bottom  view  of  a  Premier  six-cylinder 
engine  with  bottom  half  of  crank  case  removed  is  given.  This  illus- 
trates clearly  the  arrangement  of  crank  pins  and  main  bearings  when 


204 


Tlie  Modern  Gasoline  Automobile 


the  crank  shaft  is  supported  on  four  journals.    The  crank  shaft  shown 
at  Fig.  105,  B,  is  a  six-cylinder  seven-bearing  type. 


Fig.  110. — Bottom  View  of  Premier  Engine  Showing  Four-Bearing,  Six-Cylinder 
Crank  Shaft  with  Connecting  Rods  in  Place. 

Ball-Bearing  Crank  Shafts. — While  crank  shafts  are  usually  sup- 
ported in  plain  journals  there  seems  to  be  a  growing  tendency  of  late 
to  use  anti-friction  bearings  of  the  ball  type  for  their  support.  This  is 


Retention 

Nut 
Timing  Gear 


Fig.  111.— Design  of  Four-Cylinder  Crank  Shaft  Mounted  on  Two  Annular  Ball 
Bearings.  Note  Method  of  Fly-wheel  Retention  by  Key  and  Taper  and 
Bearing  Housing. 


The  Modern  Gasoline  Automobile  205 

especially  noticeable  on  block  motors  where  but  two  main  bearings  are 
utilized.  When  ball  bearings  are  selected  with  proper  relation  to  the 
load  which  obtains  they  will  give  very  satisfactory  service.  They 
permit  the  crank  shaft  to  turn  with  minimum  friction,  and  if  properly 
selected  will  never  need  adjustment.  The  drawing  at  Fig.  Ill  shows 
the  usual  method  of  mounting  a  four-cylinder  crank  shaft  on  two 
annular  ball  bearings.  The  front  end  is  supported  by  a  bearing  which 
is  clamped  in  such  a  manner  that  it  will  take  a  certain  amount  of  load 
in  a  direction  parallel  to  the  axis  of  the  shaft,  while  the  rear  end  is 
so  supported  that  the  outer  race  of  the  bearing  has  a  certain  amount 


Fig.  112. — Four-Throw,  Two-Bearing  Chalmers  Crank  Shaft  Mounted  on  Anti- 
Friction  Journals  of  the  Ball-Bearing  Type. 

of  axial  freedom  or  "  float/'  The  inner  race  or  cone  of  each  bearing 
is  firmly  clamped  against  shoulders  on  the  crank  shaft.  At  the  front 
end  of  the  crank-shaft  timing  gear  and  a  suitable  check  nut  are  used, 
while  at  the  back  end  the  bearing  is  clamped  by  a  threaded  retention 
member  between  the  fly  wheel  and  a  shoulder  on  the  crank  shaft.  The 
fly  wheel  is  held  in  place  by  a  taper  and  key  retention.  The  ball  bear- 
ings are  carried  in  a  housing  of  bronze  or  malleable  iron,  which  in 
turn  are  held  in  the  crank  case  by  bolts.  The  two-bearing  crank  shaft 
shown  at  Fig.  112  is  that  used  in  Chalmers'  motors,  while  a  three- 
bearing  crank  shaft  supported  on  anti-friction  members  of  the  ball 
type  which  has  been  used  successfully  on  Lozier  cars  is  shown  at  Fig. 


206 


The  Modern  Gasoline  Automobile 


113.  Figs.  Ill  and  112  show  designs  of  two-bearing,  four-cylinder 
crank  shafts,  such  as  used  in  block  motors  very  clearly,  while  the 
form  depicted  at  Fig.  113  forms  part  of  a  motor  having  the  cylinders 
cast  in  pairs. 


Fig.  113. — Four-Throw,  Three-Bearing  Lozier  Crank  Shaft  and  Connecting  Rod 
Assembly  Mounted  on  Three  Large  Annular  Ball  Bearings.  Note  Con- 
necting Rod  Design  and  the  Use  of  Plain  Bearings  at  Both  Wrist-pin  and 
Crank-pin  Ends. 

Fly-wheel  Construction  and  Retention. — In- explaining  the  princi- 
ple of  operation  of  the  internal  combustion  engine  it  was  made  clear 
that  there  were  four  strokes  of  the  piston  necessary  to  complete  the 
cycle  of  operation  in  any  one  cylinder,  and  of  these  but  one*  was  a 
useful  or  power  stroke.  The  gasoline  engine  would  not  be  a.  practical 


The  Modern  Gasoline  Automobile  207 

power  producer,  especially  if  made  in  one-  and  two-cylinder  patterns, 
without  some  means  of  equalizing  the  uneven  power  generation.  Con- 
sidering first  the  single-cylinder  motor,  we  find  that  we  have  but  one 
explosion  every  four  strokes,  and  as  this  represents  two  revolutions  of 
the  crank  shaft  it  will  be  evident  that  it  is  necessary  to  store  up  energy 
by  some  means  in  order  to  carry  the  crank  shaft  through  the  idle 
strokes.  This  is  accomplished  by  supplying  a  heavy  wheel  which  is 
secured  in  a  positive  manner  to  the  crank  shaft  and  which  turns  with 
it.  When  the  explosion  drives  the  piston  down  considerable  energy 
is  stored  in  the  fly-wheel  rim  and  it  will  continue  to  revolve  after  the 
impulse  given  it  has  diminished  in  value  to  a  considerable  extent.  In 
fact  there  is  enough  energy  stored  in  the  fly  wheel  of  proper  weight 
to  carry  the  piston  through  all  the  idle  strokes  and  to  equalize  the 
torque  produced.  This  insures  an  even  turning  moment  and  makes 
for  uniform  application  of  power  to  the  mechanism. 

The  fly-wheel  weight  is  dictated  largely  by  the  number  of  cylin- 
ders employed,  it  being  a  general  rule  that  the  motors  having  the  least 
number  of  cylinders  require  the  heaviest  fly  wheels.  This  means  that 
a  single-cylinder  motor  will  need  a  heavier  equalizing  member  than 
one  having  a  greater  number  of  cylinders  and  a  more  even  turning 
moment  at  the  crank  shaft.  As  an  example  of  how  the  number  of 
cylinders  directly  affects  fly-wheel  weight,  one  may  say  that  if  a  single- 
cylinder  engine  of  given  power  required  a  fly  wheel  of  two  hundred 
pounds  weight  to  equalize  the  power  effect,  a  double-cylinder  engine 
would  need  one  of  about  one  hundred  and  sixty  pounds,  a  four-cylin- 
der engine  would  use  one  weighing  but  one  hundred  pounds,  while  a 
six-cylinder  motor  would  furnish  a  uniform  torque  with  a  fly-wheel 
member  weighing  no  more  than  sixty  pounds.  Fly-wheel  weight  is 
determined  by  many  conditions,  some  of  the  important  ones  being  bore 
of  the  cylinder,  speed  of  crank-shaft  rotation,  degree  of  compression, 
and  mode  of  transmission.  It  is  common  practice  to  provide  a  fly 
wheel  somewhat  heavier  than  the  actual  requirements  on  multi-cylin- 
der motors  of  large  bore  so  that  these  may  be  more  easily  started  by 
a  person  of  average  strength. 

Fly-wheel  types  vary  from  simple  spoked  members  resembling  a 
belt  pulley  with  a  heavy  rim  to  others  having  fan-shaped  spokes  and 
light  rims.  Where  a  sliding  gear  transmission  is  used  it  is  customary 


208 


The  Modern  Gasoline  Automobile 


to  make  one  of  the  clutch  members  integral  with  the  fly  wheel.  For 
instance,  at  Fig.  114  a  typical  fan-blade  fly  wheel  adapted  for  use  with 
a  cone  clutch  is  shown.  This  has  a  central  web  member  which  forms 


Fig.  114. — Typical  Fly  Wheel  Showing  Female  Member  of  Cone  Clutch  and  Fan- 
Blade  Spokes.    Rim  is  Light  Because  of  Large  Diameter. 

the  back  of  a  saucer-shaped  casting  which  serves  as  a  female  member 
of  the  cone  clutch.  From  the  periphery  of  this,  the  spokes  radiate  to 
the  rim.^  As  the  fly  wheel  is  of  comparatively  large  diameter  the 
rim  is  lighter  than  would  be  necessary  if  the  weight  were  concentrated 
nearer  the  center  of  the  crank  shaft.  At  Fig.  115  the  rear  view  of  a 
power  plant  is  given  showing  a  simple  type  of  fan-blade  fly  wheel, 


The  Modern  Gasoline  Automobile 


209 


which  is  secured  to  the  crank  shaft  by  means  of  four  bolts.     As  this 
member  is  designed  for  use  with  a  type  of  gearset  with  the  clutches 


Fig.  115. — Rear  View  of  Overland  Power  Plant  Showing  Fan-Blade  Spoke  Fly- 
wheel Construction. 

incorporated,  it  is  not  necessary  to  provide  for  part  of  the  clutch  in 
the  fly-wheel  casting. 

The  diameter  of  a  fly  wheel  must  be  held  to  certain  limits  and 
this  restricts  the  useful  weight  one  can  put  at  the  rim.     If  the  fly 


210  The  Modern  Gasoline  Automobile 

wheel  is  placed  low  in  the  car  it  cannot  be  of  large  diameter,  because 
one  must  have  at  least  twelve  or  fourteen  inches  clearance  between  the 
bottom  of  the  fly  wheel  and  the  roadway.  Then  again,  the  factor  of 
centrifugal  force  must  be  taken  into  account,  as  when  a  fly  wheel  re- 
volves there  is  a  tendency  for  the  particles  of  which  it  is  composed  to 
fly  out  in  a  direction  tangential  to  the  circle  of  rotation,  and  this  force 
^tends  to  rupture  the  rim.  If  steel  is  used  instead  of  cast  iron,  the 
fly  wheel  may  be  of  larger  diameter,  because  the  stronger  material  has 
greater  resistance  to  this  rupturing  stress,  but  these  wheels  are  not 
easy  to  make  because  in  ordinary  motor  car  sizes  they  must  be  steel 
castings  and  are  thus  quite  costly.  For  a  cast-iron  fly  wheel  a  safe 
value  for  speed  of  rotation  of  a  point  on  the  rim  is  about  a  mile  a 
minute.  It  will  be  seen  that  the  diameter  must  be  such  that  the  fly 
wheel  may  be  run  at  maximum  speeds  without  danger  of  bursting. 

A  fly  wheel  having  a  solid  web  joining  the  hub  and  rim  is  consid- 
erably stronger  than  one  of  the  spoke  type.  The  object  of  providing 
spokes  shaped  like  fan  blades  is  to  take  advantage  of  a  suction  effect 
produced  to  draw  air  from  the  motor  compartment  and  exhaust  it 
under  the  car.  In  some  cars  the  draft  created  by  the  fly  wheel  is  de- 
pended upon  to  supply  the  air  needed  for  cooling  the  engine,  either 
by  applying  it  directly  to  the  cylinders  or  by  pulling  it  through  the 
interstices  of  a  water-cooling  radiator.  It  is  considered  desirable  to 
concentrate  as  much  of  the  weight  of  the  fly  wheel  at  the  rim  as  pos- 
sible, because  the  further  away  from  center  the  weight  is  carried  the 
more  effective  the  fly  wheel  is  as  a  reservoir  of  energy  and  equalizer 
of  torque. 

Positive  Fly-wheel  Retention  Important. — Methods  of  fly-wheel  re- 
tention vary  to  some  extent,  and  the  main  point  observed  by  most 
designers  is  to  use  as  secure  a  method  of  attaching  it  to  the  crank  shaft 
as  possible.  The  common  systems  of  retention  employed  are  shown  at 
Fig.  116.  The  simplest  of  these  is  depicted  at  A.  This  consists  merely 
of  forcing  the  shaft  into  the  fly-wheel  hub  and  keeping  the  fly  wheel 
from  turning  on  the  shaft  by  a  substantial  key  which  fits  keyways 
machined ,  in  both  shaft  and  fly-wheel  hub.  This  method  was  for- 
merly used  to  a  greater  extent  than  it  is  at  present,  but  its  use  has 
been  practically  abandoned,  except  on  marine  engines,  because  the 
means  of  fastening  was  not  reliable.  The  intermittent  application  of 


The  Modern  Gasoline  Automobile 


211 


power  to  the  fly  wheel  meant  that  its  speed  of  rotation  was  accelerated 
at  a  certain  point  of  the  crank-shaft  travel  corresponding  to  the  power 
stroke  and  checked  at  the  other,  or  idle  strokes.  This  produced  stresses 
which  tended  to  loosen  the  fly  wheel  on  the  key,  and  as  soon  as  the 
retaining  member  was  slightly  loose  a  very  disagreeable  knocking 


Fig.  116. — Outlining  Methods  of  Fly-wheel  Retention  Commonly  Used.  A — By 
Gib  Key.  B — By  Woodruff  Key,  Taper  and  Clamp  Nut.  C — By  Bolting  to 
Flange  Forged  Integrally  with  Crank  Shaft. 

sound  was  produced  by  the  hammering  action  of  the  loose  fly  wheel 
on  its  retaining  key. 

At  B  a  system  often  employed  on  types  of  crank  shafts  where  it 
is  not  practical  to  use  the  preferred  method  shown  at  C  is  outlined. 
For  instance,  when  ball  bearings  are  applied  it  is  necessary  that  they 
be  put  on  the  shaft  from  each  end  and  if  a  flange  was  formed  integral 
it  would  not  be  possible  to  use  ball  bearings  except  of  very  large  bore. 


212 


The  Modern  Gasoline  Automobile 


Then  again,  some  engineers  using  alloy  steel  for  crank-shaft  construc- 
tion machine  it  from  a  slab  of  that  material,  and  in  order  to  reduce 
cost  of  manufacture  no  attempt  is  made  to  form  the  flange  integral 
with  the  shaft.  In  this  the  end  of  the  shaft  designed  to  support  the 


Trammel 


Fig.  117. — Showing  Method  of  Marking  Rim  of  Six-Cylinder  Fly  Wheel  for 
Guiding  Repairman  or  Motorist  to  Retain  Correct  Valve  Timing. 

fly  wheel  is  tapered,  as  is  also  the  fly-wheel  hub.  In  addition  to  the 
taper  a  Woodruff  key  is  usually  let  into  the  shaft  and  keyway  cut  into 
the  fly-wheel  hub  to  receive  it.  When  the  fly  wheel  is  forced  on  the 
taper  by  the  clamping  nut  it  is  firmly  retained  by  the  key,  and  at  the 


The  Modern  Gasoline  Automobile  213 

same  time  the  wedging  effect  of  the  taper  and  the  pressure  of  the 
clamping  nut  prevents  the  fly  wheel  from  loosening.  The  fly  wheel  at 
B  has  a  portion  of  the  rim  machined  on  a  taper,  so  it  can  receive  the 
male  member  of  a  cone-type  clutch. 

The  fly  wheel  shown  at  C  is  held  by  the  preferred  method.  In 
forging  the  crank  shaft  a  flange  is  formed  integral  and  the  fly  wheel 
is  secured  to  this  flange  by  means  of  suitable  retaining  screws  or  bolts. 
If  these  are  properly  fitted  it  is  practically  impossible  for  the  fly 
wheel  to  loosen  on  the  flange,  and  as  the  flange  is  a  part  of  the  shaft 
it  is  obviously  impossible  for  it  to  become  separated  therefrom.  The 
fly  wheel  shown  at  C  is  provided  with  a  casing  formed  integral  which 
is  designed  to  receive  a  clutch  of  the  multiple-disk  pattern. 

The  writer  has  previously  explained  the  action  of  the  valve  mech- 
anism and  diagrams  have  been  presented  to  show  the  sequence  of  the 
strokes.  Most  manufacturers  mark  the  fly  wheel  with  the  various 
points  at  which  valves  should  open  or  close.  This  not  only  facili- 
tates work  at  the  plant  of  the  producer,  but  it  insures  that  the  timing 
will  be  restored  to  the  proper  point  in  eveiit  of  taking  the  engine  down 
for  repair  at  some  garage  or  machine  shop.  The  various  points  are 
laid  out  on  the  fly-wheel  periphery  by  means  of  steel  stamps  or  letters, 
which  may  be  easily  interpreted.  The  position  of  these  lines  is  deter- 
mined by  the  peculiarities  of  that  specific  engine,  and  will  vary  in 
the  different  designs.  The  layout  is  always  made  with  reference  to 
some  fixed  point  on  the  motor  bed,  this  usually  being  a  small  metal 
pointer  attached  to  a  center  point  and  known  as  a  "  trammel."  The 
various  points  at  which  valves  should  open  and  close  for  a  typical  six- 
cylinder  engine  are  clearly  shown  laid  out  on  the  fly-wheel  rim  at 
Fig.  117. 

Engine-Base  Construction. — One  of  the  important  parts  of  the 
power  plant  is  the  substantial  casing  or  bed  member,  which  is  em- 
ployed to  support  the  cylinders  and  crank  shaft  and  which  is  attached 
directly  to  the  motor-car  frame.  This  will  vary  widely  in  form,  but 
as  a  general  thing  it  is  an  approximately  cylindrical  member  which 
may  be  divided  either  vertically  or  horizontally  in  two  or  more  parts. 
Automobile  crank  cases  are  usually  made  of  aluminum,  a  material 
which  has  about  the  same  strength  as  cast  iron,  but  which  only  weighs 
a  third  as  much.  In  some  cases  cast  iron  is  employed,  but  is  not 


214 


The  Modern  Gasoline  Automobile 


favored  by  most  engineers  because  of  its  brittle  nature  and  low  re- 
sistance to  tensile  stresses.  Where  exceptional  strength  is  needed  al- 
loys of  bronze  are  used,  and  in  some  cases  where  cars  are  produced  in 
large  quantities  a  portion  of  the  crank  case  may  be  a  sheet  steel  or 
aluminum  stamping. 

Crank  cases  are  always  large  enough  to  permit  the  crank  shaft  and 
parts  attached  to  it  to  turn  inside  and  obviously  its  length  is  deter- 


Tig.  118.— Crank  Case  of  Reo  Four-Cylinder  Motor,  a  Barrel  Type  with  Ends 
Closed  by  Plates  which  Support  Crank  Shaft. 

mined  by  the  number  of  cylinders  and  their  disposition.  The  crank 
case  of  the  single-cylinder  or  double-opposed  cylinder  engine  would 
be  substantially  the  same  in  length.  That  of  a  four-cylinder  will  vary 
in  length  with  the  method  of  casting  the  cylinder.  When  the  four 
cylinders  are  cast  in  one  unit  and  a  two-bearing  crank  shaft  is  used,  the 
crank  case  is  a  very  compact  and  short  member.  When  a  three-bearing 
crank  shaft  is  utilized  and  the  cylinders  are  cast  in  pairs,  the  engine 
base  is  longer  than  it  would  be  to  support  a  block  casting,  but  is 


The  Modern  Gasoline  Automobile 


215 


shorter  than  one  designed  to  sustain  individual  cylinder  castings  and 
a  five-bearing  crank  shaft. 

A  four-cylinder  crank  case  of  the  barrel  type  is  shown  at  Fig.  118. 
The  construction  calls  for  the  use  of  end-bearing  plates,  which  carry 
the  front  and  rear  main  journals.  In  order  to  gain  access  to  the  in- 
terior, large  openings  are  provided  at  the  side  of  the  case  and  closed 
by  plates  when  the  assembly  is  completed.  The  cylinders  are  held  in 
place  by  a  series  of  stud  bolts  screwed  into  the  top  of  the  case,  and  a 
similar  method  of  retention  is  utilized  for  the  end  plates.  A  projec- 
tion from  the  side  serves  to  house  the  cam  shaft,  while  the  motor- 


Fig.  119. — Crank  Case  of  Corbin  "  40  "  Power  Plant  Made  in  Two  Halves. 
Crank-Shaft  Bearings  and  Caps  Secured  to  Upper  Half,  which  also  Has  Sup- 
porting Arms  Cast  Integral.  Lower  Portion  of  Crank  Case  Simply  Acts  as 
Oil  Container.  This  is  the  Common  Construction. 

timing  gears  are  protected  by  a  separate  casting  member,  which  is 
part  of  the  front  bearing  plate.  It  is  now  common  construction  to 
cast  an  oil  container  integral  with  the  bottom  of  the  engine  base  and 
to  draw  the  lubricating  oil  from  it  by  means  of  a  pump.  The  arms 


216 


The  Modern  Gasoline  Automobile 


by  which  the  motor  is  supported  in  the  frame  are  substantial-ribbed 
members  cast  integrally. 

The  approved  method  of  crank-case  construction  favored  by  the 
majority  of  engineers  is  shown  at  Fig.  119,  bottom  side  up.  The 
upper  half  not  only  forms  a  bed  for  the  cylinder  but  is  used  to  hold 
the  crank  shaft  as  well.  In  the  illustration  the  three-bearing  crank 
shaft  is  shown  resting  in  the  upper  main  bearing  boxes  which  form 
part  of  the  case,  while  the  lower  brasses  are  in  the  form  of  separately 
cast  caps  retained  by  suitable  bolts.  In  the  construction  outlined  the 
bottom  part  of  the  case  serves  merely  as  an  oil  container  and  a  pro- 
tection for  the  interior  mechanism  of  the  motor. 


Fig.  120.— Bottom  View  of  Inter-State  Power  Plant.  Crank  Case  a  Barrel  Form 
with  Removable  Bottom  Plate  to  Permit  Access  to  Engine  Interior.  Im- 
portant Power  Plant  Parts  Clearly  Shown. 

In  some  instances  where  barrel-type  crank  cases  are  employed,  in- 
stead of  using  hand  holes  for  adjustment  in  the  side,  the  design  is  as 
shown  at  Fig.  120.  The  bottom  of  the  crank  case  is  left  open  in  cast- 
ing and  is  closed  by  a  large  plate.  The  interior  parts  of  the  engine 


217 


218  The  Modern  Gasoline  Automobile 


are  clearly  depicted,  as  they  appear  viewed  from  the  bottom,  and  the 
accessibility  afforded  by  this  design  should  be  readily  perceived.  En- 
gineers who  favor  unit  power  plants  often  include  a  portion  of  the 
crank  case  with  the  housing  for  the  clutch  and  gearset.  Such  a 
construction  is  clearly  shown  at  Fig.  121.  It  will  be  seen  that  a  sub- 
stantial yoke  member  which  encircles  the  fly  wheel  is  used  to  join  the 
gear  case  to  the  engine  base.  In  this  view  the  method  of  retaining 
the  five-bearing  crank  shaft  to  the  upper  half  of  the  case  is  also 
shown.  In  designing  crank  cases  the  main  thing  to  be  considered  is 
to  have  it  of  ample  strength  and  to  arrange  the  various  parts  so  that 
the  interior  mechanism  may  be  reached  without  dismantling  the  entire 
engine  when  adjustments  are  necessary. 

Typical  Two-Cycle  Motors. — As  a  general  rule  the  two-stroke  cycle 
engines  that  have  been  adapted  for  automobile  propulsion  differ  ma- 
terially from  the  simple  forms  previously  described.  Some  makers, 
who  use  the  simple  form,  have  been  able  to  secure  very  satisfactory, 
results  in  practice  by  careful  attention  to  port  design.  When  a  two- 
cycle  motor  is  to  be  used  for  motor-boat  propulsion,  it  is  a  moderate 
speed  proposition  and  great  flexibility  or  efficiency  are  not  sought.  In 
the  automobile,  however,  the  conditions  that  obtain  make  it  "necessary 
to  design  the  power  plant  in  such  a  way  that  it  would  have  a  wide 
range  of  speed  and  so  that  it  can  be  easily  accelerated  from  its  lowest 
to  its  highest  speed  without  missing  explosions  or  running  irregularly. 

A  sectional  view  through  the  cylinder  of  the  Amplex  two-cycle 
motor  is  shown  at  Fig.  122,  A.  This  motor  is  a  simple  construction 
which  resembles  the  marine  type  in  general  design,  though  great  care 
has  been  taken  in  proportioning  the  ports  and  gas  passages  to  obtain 
the  flexibility  which  is  so  essential  to  the  motor-car  power  plant.  This 
motor  is  a  three-port  type  and  the  gas  is  taken  into  the  engine  base 
through  ports  which  are  uncovered  by  the  piston  when  it  reaches  the, 
end  of  its  compression  stroke.  When  the  parts  are  in  the  position 
shown  at  A,  the  piston  has  reached  the  top  of  its  stroke  and  the  com- 
pressed gas  in  the  cylinder  is  ready  for  ignition.  At  the  same  time 
the  inlet  ports  just  at  the  bottom  of  the  piston  have  been  uncovered  I 
and  the  gas  flows  through  the  intake  manifold  from  the  carburetor. 
In  the  other  view  shown  at  B,  the  position  of  the  parts  when  the  pis- 
ton has  completed  its  power  stroke  is  depicted.  The  exhaust  port  is 


219 


220  The  Modern  Gasoline  Automobile 

fully  opened  and  the  burned  gases  are  discharged  through  it.  Com- 
munication is  also  made  between  the  engine  base  where  the  charge 
has  received  preliminary  compression  necessary  to  insure  its  transfer 
through  the  safety  screen  and  the  open  ports  in  the  cylinder  wall. 
The  entering  fresh  gas  is  deflected  to  the  top  of  the  cylinder  by  the 
deflector  plate  provided  on  the  top  of  the  piston,  as  is  usual  practice. 
The  Amplex  motor  is  a  four-cylinder  type  and  gives  very  satisfactory 
results  in  practice. 

The  Legros  two-cycle  motor,  which  is  of  French  derivation,  em- 
bodies a  distributor  valve  and  a  peculiar  arrangement  of  pistons.  In 
this  construction  a  stationary  member  is  placed  inside  of  the  regular 
working  piston,  and  it  is  the  space  between  these  members  that  is 
utilized  to  store  the  gas  taken  in,  prior  to  transferring  it  from  the 
pump  portion  of  the  engine  to  the  combustion  chamber.  The  action 
is  very  similar  to  that  of  the  usual  form  of  differential  piston  motor. 
When  the  piston  goes  up  on  the  compression  stroke  it  draws  in  a 
charge  of  gas  from  the  carburetor  through  the  rotary  distributor 
valve  and  up  through  the  passage  which  joins  the  valve  chambers  to 
the  space  between  the  stationary  and  movable  pistons.  When  the 
piston  reaches  the  top  of  its  stroke  the  rotary  valve  turns  to  such  a 
position  that  it  cuts  off  the  carburetor  from  the  pumping  chamber  and 
provides  communication  between  the  pumping  chamber  and  the  cylin- 
der by  means  of  the  usual  transfer  passage  and  inlet  ports  cored  into 
the  cylinder  wall.  Otherwise  the  action  is  just  the  same  as  that  of 
the  more  simple  forms  of  engines.  The  construction  of  this  motor  is 
clearly  shown  at  Fig.  123,  and  as  all  parts  are  clearly  indicated  the 
principle  of  operation  should  be  easily  grasped. 

Another  differential  piston  motor  designed  by  a  French  engineer, 
Monsieur  Cote,  is  shown  at  Fig.  124.  In  this  a  double-diameter 
piston  is  used  and  the  cylinder  is  formed  so  that  the  smaller  of  these 
members  fits  the  upper  portion  while  the  large  end  of  the  piston  fits 
the  correspondingly  enlarged  lower  portion.  The  functions  of  com- 
pression and  explosion  of  the  charge  take  place  in  the  smaller  cylinder, 
while  the  lower  member  acts  as  a  pump.  On  every  downstroke  of  the 
piston  a  charge  of  gas  is  drawn  into  the  annular  space  between  the 
piston  and  cylinder  wall,  and  on  every  upward  stroke  it  is  compressed 
and  forced  into  the  working  cylinder  adjacent.  The  construction  out- 


Spark  Plug 


Combustion  Chamber. 


Water  Outlet 


Water  Space 


Distributor  Valve 


Carburetor 
Balancs  Weight 
Crankshaft 

Flywheel 


Cranhcase 


Fig.  123. — Sectional  View  Showing  Construction  of  Legros  (French)  Motor 

Defining  Peculiar  Cylinder  Construction. 

221 


222 


The  Modern  Gasoline  Automobile 


lined  is  applicable  only  to  motors  having  an  even  numlx-r  of  cylinders, 
and  the  arrangement  must  be  sucii  that  they  will  work  in  pairs  and 
that  the  piston  in  one  cylinder  will  be  at  one  end  of  its  stroke  while 


Spark  Plug 


Compression  Relief  Cock 
Combustion  Chamber 


Cylinder 

Water  Space 


Exhaust  Pipe 


Crankcase 


Fig.  124.— The  Cote  (French)  Two-Cycle  Motor  is  a  Good  Example  of  the  Type 
»    Employing  a  Two-Diameter  Piston  and  Distributor  Valve. 

that  of  its  mate  is  in  the  other  extreme  position.    The  peculiar  type 
of  transfer  passage  depicted  is  necessary  because  the  pumping  por- 


The  Modern  Gasoline  Automobile 


223 


tion  of  one  cylinder  must  be  joined  to  the  working  portion  of  the  other 
member.  Outside  of  peculiarities  of  construction,  the  operating  cycle 
is  just  the  same  as  other  two-stroke  engines,  and  an  explosion  is  ob- 
tained in  each  cylinder  every  two  strokes  of  the  piston. 


Sp»rk  Plug 


125.— The  Rayner  (English)  Two-Cycle  Motor  Employs  Distinctive  Double- 
Piston  Arrangement.  A — Side  View  Showing  Crank  Shaft  and  Connecting 
Rods.  B — End  Section  Showing  Relative  Angularity  of  Connecting  Rods. 
C — Inner  Piston  Uncovers  Inlet  Ports;  Outer  Piston  Covers  Exhaust  Pas- 
sages. 

An  unconventional  two-cycle  engine  of  English  design  is  shown 
at  Fig.  125.  Two  pistons  are  used,  one  working  inside  of  the  other; 
the  outer  member  carries  an  annular  flange  which  fits  the  enlarged 
bore  of  the  cylinder  and  acts  as  a  pump  for  taking  in  the  gas  and  sub- 


224  The  Modern  Gasoline  Automobile 

jecting  it  to  preliminary  compression.  The  pump  chamber  is  divided 
from  the  crank  case  by  a  flange,  which  also  acts  as  a  guiding  member 
for  the  bottom  of  the  large  piston.  At  the  end  of  the  downstroke 
each  piston  uncovers  a  ring  of  ports,  the  outer  member  opening  the 
exhaust  while  the  inner  piston  controls  the  inlet  openings.  A  pecu- 
liar form  of  crank  shaft  having  two  throws  for  each  cylinder  is  used, 
and  the  crank  to  which  the  inner  piston  is  attached  has  twice  the 
amount  of  throw  the  crank  connected  to  the  larger  member  has.  This 
means  that  both  pistons  work  in  the  same  direction,  but  that  the 
inner  member  travels  twice  the  distance  the  big  piston  does.  The, 
crank  which  controls  the  movement  of  the  outer  piston  is  given  a  lead 
of  about  twenty  degrees  so  that  the  exhaust  ports  are  opened  at  the 
proper  time  in  relation  to  the  opening  of  the  inlet  passages. 

When  the  pistons  travel  on  the  upstroke,  the  inner  one  is  com- 
pressing a  charge  previously  supplied  the  working  cylinder  and  simul- 
taneously fresh  gas  is  being  inspired  into  the  pump  chamber.  When 
the  pistons  reach  the  top  of  the  stroke  the  spark  takes  place  and 
the  resulting  explosion  drives  the  piston  down  and  imparts  power  to 
the  crank  shaft  in  the  usual  manner.  At  the  same  time  that  the  pis- 
tons are  driven  down  by  the  explosion,  the  new  charge  which  has  been 
drawn  in  through  the  pump  chamber  is  partially  compressed.  Near  the 
end  of  the  stroke  the  outer  piston  uncovers  the  exhaust  ports,  and  the 
burned  gases  escape  by  virtue  of  their  pressure.  The  inlet  ports  open 
and  new  gas  enters  the  cylinder  in  the  usual  manner  and  is  directed  to 
the  top  of  the  cylinder  by  the  peculiar  formation  of  the  outer  piston, 
which  acts  as  a  chimney  to  direct  the  gases  to  the  top  of  the  combus- 
tion chamber.  As  the  new  charge  enters  at  considerable  speed  the 
high  velocity  of  the  gas  forces  out  the  burned  products  and  insures 
thorough  scavenging.  The  view  at  A  is  a  side  section  and  depicts  the 
arrangement  of  the  pistons  relative  to  each  other  and  the  peculiar 
arrangement  of  the  crank  shaft.  At  B  an  end  section  is  presented, 
this  to  show  the  angularity  of  connecting  rods,  showing  how  the  short 
throw  crank  is  given  a  slight  lead  over  that  which  works  the  inner 
piston. v  The  inset  at  C  is  given  to  enable  the  reader  to  understand  the 
principle  involved  in  controlling  the  intake  and  exhaust  ports. 

Typical  Four-Cycle  Power  Plants. — The  writer  has  previously  men- 
tioned the  fact  that  most  engineers  favor  the  four-cycle  form  of  power 


The  Modern  Gasoline  Automobile 


225 


plant,  and  the  majority  of  the  descriptive  matter  presented  in  this 
chapter  has  dealt  specifically  with  this  form  of  engine.  As  a  fitting 
conclusion  a  brief  description  of  some  representative  American  power 
plants  will  be  given.  At  Fig.  126  the  inlet  side  of  a  four-cylinder 
water-cooled  motor  is  illustrated,  while  the  exhaust  side  of  the  same 
power  plant  is  depicted  at  Fig.  127.  It  will  be  observed  that  the 


Fig.  126.— Inlet  Side  of  Typical  Four-Cylinder  Power  Plant  Showing  Carburetor 

and  Magneto  Placing. 

carburetor  and  magneto  are  placed  on  the  side  of  the  motor  with  the 
inlet  valves  while  the  water  pump  is  installed  on  the  exhaust  side. 
The  front  end  of  the  power  plant  is  supported  by  a  steel  member 
bolted  to  the  upper  part  of  the  crank  case,  while  the  rear  portion  is 
fastened  to  the  frame  by  means  of  arms  cast  integral  with  the  upper 
half  of  the  engine  base.  The  cjdinders  are  cast  in  pairs  with  water 
jackets  integral,  while  the  engine  base  is  made  in  three  pieces  and  is 
divided  horizontally. 


Fig.  127. — Exhaust  Side  of  Four-Cylinder  Power  Plant  Showing  Water  Pump 

Location. 


Fig.  128. — Valve  Side  Regal  Motor  Showing  Compactness  of  Design  Possible 
with  L  Cylinder  Construction.  Note  Manifold  Placing  and  Magneto  and 
Carburetor  Location. 

226 


The  Modern  Gasoline  Automobile 


227 


The  valve  side  of  a  light  four-cylinder  power  plant  used  on  Regal 
motor  cars  is  shown  at  Fig.  128.  This  demonstrates  clearly  the  com- 
pact design  possible  with  "  L  "  head  cylinders,  which  permits  placing 
both  inlet  and  exhaust  valves  on  the  same  side  of  the  motor.  The 
placing  of  the  magneto  and  the  method  of  protecting  the  wires  lead- 
ing from  it  to  the  spark  plugs  at  the  top  of  the  cylinders,  as  well  as 


Fig.  129.— Exhaust  Side  of  Columbia  "  Mark  85  "  Motor.     Note  Enclosed  Valve 
Springs  and  Arrangement  of  Parts. 

the  method  of  retaining  the  inlet  and  exhaust  manifolds,  are  clearly 
outlined.  No  water  pump  is  employed  on  this  engine,  the  natural 
or  thermo-siphon  system  of  water  circulation  being  depended  upon  to 
adequately  cool  the  cylinders. 

The  exhaust  side  of  the  Columbia  Mark  85  four-cylinder  motor  is 
illustrated  at  Fig.  129.  In  this  the  cylinders  are  of  the  "  T  "  head 
type  and  are  cast  in  pairs.  Attention  is  called  to  the  method  of  en- 


228  The  Modern  Gasoline  Automobile 

closing  the  valve  springs  and  operating  plungers  to  keep  them  free  of 
grit  and  to  minimize  noise  incidental  to  the  valve  mechanism.  The 
water  pump  is  driven  by  a  shaft  extending  from  the  gear  case  at  the 
front  end  of  the  motor  while  the  oil-circulating  pump  is  suspended 
at  the  rear  of  the  crank  case  between  the  oil  container  and  the  fly 
wheel. 

While  the  greatest  number  of  automobiles  use  four-cylinder  power 
plants,  there  are  a  number  of  manufacturers  who  provide  engines  hav- 


Fig.  130. — Inlet  Side  of  Matheson  "  Silent  Six  "  Power  Plant,  an  Overhead  Valve 

Type. 

ing  six  cylinders.  As  a  rule  these  do  not  differ  materially  from  the 
four-cylinder  forms,  except  for  the  addition  of  an  extra  pair  of  cylin- 
ders and  the  added  length  to  the  crank  case  that  this  makes  necessary. 
The  six-cylinder  motor  shown  at  Fig.  130  is  a  distinctive  construction 
in  which  the  cylinders  are  cast  in  pairs  and  have  valves  in  the  head. 
A  very  compact  power  plant  is  made  possible  by  the  peculiar  form  of 
the  cylinder  castings  which  have  flat  ends  so  that  they  can  be  placed 
very  close  together.  It  is  seldom  that  more  than  six  cylinders  are 
used,  but  there  have  been  automobiles  made  for  racing  purposes  that 
had  eight  and  even  twelve  cylinders. 


The  Modern  Gasoline  Automobile 


229 


When  an  eight-cylinder  motor  is  used  it  is  usually  of  the  "  V  '; 
type,  i.  e.,  the  cylinders  are  arranged  in  two  sets  of  four,  as  shown  at 
Fig.  131.  This  view  represents  a  motor  which  has  been  designed  for 


Fig.  131. — View  of  Eight-Cylinder  Hendee  Motor,  a  Type  Seldom  Used  on 
Motor  Cars,  but  Popular  for  Aviation.  Eight-Cylinder  Motors  Designed 
for  Automobile  Propulsion  are  Always  of  the  V  Type,  which  Permits  Com- 
pactness and  no  Greater  Overall  than  the  Usual  Four-Cylinder  Power  Unit. 

aeronautic  service,  but  when  eight-cylinder  power  plants  are  used  for 
automobile  propulsion  they  are  built  very  much  the  same.  The  reason 
that  the  cylinders  are  arranged  opposite  each  other  and  at  an  angle  in- 
stead of  being  placed  one  after  the  other  is  that  the  "  V  "  construe- 


230 


The  Modern  Gasoline  Automobile 


tion  makes  it  possible  to  use  a  crank  case  which  is  not  much  longer  or 
heavier  than  would  be  needed  for  the  conventional  four-cylinder  mo- 
tor. An  eight-cylinder  engine  is  rather  complicated,  and  difficult]  < 
obtain  in  lubrication,  cooling,  and  ignition,  so  that  this  type  is  no1 
apt  to  become  very  popular,  even  though  it  furnishes  power  very  stead- 
ily when  all  cylinders  are  working.  An  eight-cylinder  motor  of  the 
four-cycle  type  will  give  four  explosions  every  revolution  of  the  crank 
shaft  or  one  impulse  every  quarter  turn.  A  car  equipped  with  such 
a  motor  would  be  much  more  flexible  than  with  a  lesser  number  of 
cylinders,  but  as  the  four-  and  six-cylinder  forms  give  practically  a 
uniform  and  regular  turning  movement  of  the  crank  shaft  it  is  not 
considered  advisable  to  use  more  than  six  cylinders  in  touring  cars 
and  four  cylinders  in  motor  trucks. 


CHAPTER  V 

Defining  the  Liquid  Fuels  Commonly  Used  and  Methods  of  Vaporizing  to 
Obtain  Explosive  Gas — Methods  of  Carrying  Fuel  in  Automobiles — De- 
velopment of  Modern  Carburetor  from  Early  Vaporizer  Forms — Elements 
of  Carburetor  Design  Outlined — Typical  Gasoline  Vaporizers  Described  in 
Detail — How  Kerosene  May  be  Utilized — Discussing  Fuel  Supply  by  Direct 
Injection — Inlet  and  Exhaust  Manifold  Design — Muffler  Forms  in  Common 
Use. 

THERE  is  no  appliance  that  has  more  material  value  upon  the  effi- 
ciency of  the  internal  combustion  motor  than  the  carburetor  or  vapor- 
izer which  supplies  the  explosive  gas  to  the  cylinders.  It  is  only  in 
recent  years  that  engineers  have  realized  the  importance  of  using  car- 
buretors that  are  efficient  and  that  are  so  strongly  made  that  there 
will  be  little  liability  of  derangement.  As  the  power  obtained  from 
the  gas  engine  depends  upon  the  combustion  of  fuel  in  the  cylinders, 
it  is  evident  that  if  the  gas  supplied  does  not  have  the  proper  propor- 
tions of  elements  to  insure  rapid  combustion  the  efficiency  of  the 
engine  will  be  low.  When  a  gas  engine  is  used  as  a  stationary  instal- 
lation it  is  possible  to  use  ordinary  illuminating  or  natural  gas  for 
fuel,  but  when  this  prime  mover  is  applied  to  automobile  or  marine 
service  it  is  evident  that  considerable  difficulty  would  be  experienced 
in  carrying  enough  compressed  coal  gas  to  supply  the  engine  for  even 
a  very  short  trip.  Fortunately,  the  development  of  the  internal  com- 
bustion motor  was  not  delayed  by  the  lack  of  suitable  fuel. 

Engineers  were  familiar  with  the  properties  of  certain  liquids 
which  gave  off  vapors  that  could  be  mixed  with  air  to  form  an  explo- 
sive gas  which  burned  very  well  in  the  engine  cylinders.  A  very  small 
quantity  of  such  liquids  would  suffice  for  a  very  satisfactory  period  of 
operation.  The  problem  to  be  solved  before  these  liquids  could  be 
applied  in  a  practical  manner  was  to  evolve  suitable  apparatus  for 
vaporizing  them  without  waste.  Among  the  liquids  that  can  be  com- 
bined with  air  and  burned,  gasoline  is  the  most  common  and  is  the 

231 


232  The  Modern  Gasoline  Automobile 

fuel  utilized  by  the  majority  of  internal  combustion  engines  employed 
in  self-propelled  conveyances. 

The  widely  increasing  scope  of  usefulness  of  the  internal  combus- 
tion motor  has  made  it  imperative  that  other  fuels  be  applied  in  some 
instances  because  the  supply  of  gasoline  may  in  time  become  inade- 
quate to  supply  the  demand.  In  fact,  abroad  this  fuel  sells  for  fifty  to 
two  hundred  per  cent  more  than  it  does  in  America  because  most  of 
the  gasoline  used  must  be  imported  from  this  country  or  Russia. 
Because  of  this  foreign  engineers  have  experimented  widely  with' 
other  substances,  such  as  alcohol,  benzol,  and  kerosene.  The  proper- 
ties of  these  fuels,  their  derivation  and  use  should  be  considered 
fully  before  describing  the  types  of  apparatus  utilized  for  vaporizing 
them. 

Distillates  of  Crude  Petroleum. — Crude  petroleum  is  found  in  small 
quantities  in  almost  all  parts  of  the  world,  but  a  large  portion  of  that 
produced  commercially  is  derived  from  American  wells.  The  petro- 
leum obtained  in  this  country  yields  more  of  the  volatile  products  than 
those  of  foreign  production,  and  for  that  reason  the  demand  for  it  is 
greater.  The  oil  fields  of  this  country  are  found  in  Pennsylvania, 
Indiana,  and  Ohio,  and  the  crude  petroleum  is  usually  in  association 
with  natural  gas.  This  mineral  oil  is  an  agent  from  which  many 
compounds  and  products  are  derived,  and  the  products  will  vary  from 
heavy  sludges,  such  as  asphalt,  to  the  lighter  and  more  volatile  com- 
ponents, some  of  which  will  evaporate  very  easily  at  ordinary  tem- 
peratures. 

The  compounds  derived  from  crude  petroleum  are  composed  prin- 
cipally of  hydrogen  and  carbon  and  are  termed  "  Hrdro-Carbons."  In 
the  crude  product  one  finds  many  impurities,  such  as  free  carbon, 
sulphur,  and  various  earthy  elements.  Before  the  oil  can  be  utilized 
it  must  be  subjected  to  a  process  of  purifying  which  is  known  as  re- 
fining, and  it  is  during  this  process,  which  is  one  of  destructive  dis- 
tillation, that  the  various  liquids  are  separated.  The  oil  is  broken  up 
into  three  main  groups  of  products  as  follows :  Highly  volatile,  naph- 
tha, benzine,  gasoline,  eight  to  ten  per  cent.  Light  oils,  such  as  kero- 
sene and  light  lubricating  oils,  seventy  to  eighty  per  cent.  Heavy  oils 
or  residuum,  five  to  nine  per  cent.  From  the  foregoing  it  will  be  seen 
that  the  available  supply  of  gasoline  is  determined  largely  by  the  de- 


The  Mo'dern  Gasoline  Automobile  233 

mand  existing  for  the  light  oils  forming  the  larger  part  of  the  prod- 
ucts derived  from  crude  petroleum. 

As  a  very  small  portion  of  the  distillates  can  be  used  with  ordinary 
vaporizing  devices  any  improvements  to  make  possible  the  use  of  less 
liquid  or  utilize  the  cheaper  fuels,  such  as  kerosene,  will  be  of  great 
value  in  increasing  the  usefulness  of  internal  •  combustion  motors. 
Considerable  attention  is  being  given  to  mixing  devices  which  will 
permit  the  use  of  kerosene,  and  many  authorities  have  agreed  that  this 
material  or  alcohol  will  be  the  fuel  of  the  future.  To  show  the  enor- 
mous consumption  of  gasoline  in  this  country,  it  has  been  said  that  if 
all  of  the  engines  in  use  which  depended  on  this  fuel  were  to  be  oper- 
ated continuously  together  for  a  ten-hour  day  that  over  five  million 
gallons  of  liquid  would  be  consumed.  When  one  considers  that  the 
number  of  explosive  engines  is  constantly  augmenting  it  will  not  be 
difficult  to  perceive  the  reason  why  the  development  of  devices  to  use 
fuels  other  than  gasoline  should  be  encouraged. 

Benzol  and  Its  Properties. — In  England,  where  gasoline  sells  for 
fifty  cents  a  gallon  or  one  hundred  and  fifty  per  cent  more  than  the 
average  price  in  this  country,  engineers  have  sought  to  use  benzol, 
which  is  said  to  be  adaptable  to  the  present  types  of  motors  without 
change,  and  in  cases  where  it  has  been  used  as  much  power  is  obtained 
as  with  gasoline.  This  material  is  a  by-product  incidental  to  the 
manufacture  of  illuminating  gas  and  coke,  and  while  it  was  formerly 
distilled  from  coal-tar  and  obtained  only  in  small  quantities,  improved 
methods  make  it  possible  to  produce  about  three  gallons  from  every 
ton  of  coal  changed  into  coke  or  gas.  The  former  material  was  at  one 
time  produced  by  a  process  which  permitted  the  gas  to  escape,  but  at 
the  present  time  this  is  retained  and  condensed  to  form  benzol.  The 
crude  product  is  a  foul-smelling  liquid  which  has  about  the  same  con- 
sistency and  color  as  heavy  ale.  When  subjected  to  a  refining  process 
the  dirty  liquid  is  converted  to  one  that  is  about  the  same  color  as 
water. 

Benzol  is  not  so  volatile  as  gasoline,  but  it  is  claimed  that  a  motor 
may  be  started  without  difficulty  with  this  fuel  supplied  to  a  carbu- 
retor of  ordinary  construction.  Owing  to  the  greater  number  of  heat 
units  it  contains,  it  is  said  it  will  develop  more  power  than  gasoline, 
and  as  it  will '  not  evaporate  so  readily  it  does  not  become  stale  or 


234  The  Modern  Gasoline  Automobile 

heavy  by  the  vaporization  of  the  lighter  constituents.  A  disadvantage 
incidental  to  its  use  has  been  that  owing  to  it  being  richer  in  carbon 
than  gasoline  it  would  deposit  more  of  this  substance  on  the  piston 
head  and  interior  of  the  combustion  chamber.  While  this  may  be  true 
of  a  poorly  refined  benzol  and  when  mixture  proportions  are  not  cor- 
rect, it  applies  equally  well  when  low  grades  of  gasoline  are  used  and 
when  the  mixture  of  gasoline  vapor  and  air  supplied  the  cylinders  is 
too  rich. 

Special  Vaporizers  Needed  for  Kerosene. — As  kerosene  forms  one 
of  the  larger  portions  of  the  distillates  of  crude  oil  it  is  apparent  that 
if  this  material  could  be  used  as  fuel  for  internal  combustion  engines 
it  might  replace  gasoline  to  a  certain  extent.  If  considered  from  a 
point  of  view  of  heat  units  contained  or  heating  value  kerosene  would 
be  a  better  fuel  than  gasoline,  though  considering  it  with  its  other 
disadvantages  in  mind  it  is  not  so  suitable  for  use  in  existing  types 
of  motors.  The  chief  difficulty  which  retards  its  use  is  that  it  will 
riot  vaporize  readily  at  ordinary  temperatures,  and  before  it  will  evap- 
orate sufficiently  to  form  a  gas  with  air  it  must  be  heated.  This  calls 
for  specially  constructed  vaporizing  devices  and  jacketed  manifolds, 
which  will  be  described  in  proper  sequence.  Owing  to  the  low  rate  of 
evaporation  it  is  contended  that  it  cannot  be  used  successfully  on  high- 
speed motors  where  flexibility  of  control  is  desired  and  where  the 
engine  must  be  accelerated  from  its  minimum  to  the  highest  speed  in 
a  short  time.  On  slow  and  moderate  speed  motors,  such  as  used  for 
stationary  and  marine  service,  ^kerosene  has  been  employed  with  some 
degree  of  success.  It  contains  more  carbon  in  its  composition,  and  as 
the  combustion  of  kerosene  vapor  is  not  so  apt  to  be  as  complete  as 
gasoline  gas,  more  carbon  will  be  deposited  in  the  interior  of  the  com- 
bustion chamber  than  when  gasoline  is  burned. 

Advantages  of  Alcohol. — Considerable  experimenting  with  alcohol 
has  been  done  by  French  and  German  engineers,  and  there  are  many 
points  to  be  considered  in  its  favor  when  discussing  its  value  as  a  fuel. 
Alcohol,  instead  of  being  derived  from  natural  mineral  deposits,  which 
become  more  and  more  depleted  as  the  demands  increase,  is  derived 
from  various  plants  and  vegetables  and  is  the  one  fuel  that  can  be 
produced  in  quantities  that  could  be  augmented  as  the  demand  for  it 
increased.  The  vegetable  substances  which  are  distilled  to  make  alco- 


The  Modern  Gasoline  Automobile  235 

hoi  are  reproduced  each  cycle  of  seasons,  and  in  tropical  countries 
there  is  no  cessation  to  the  growth  of  the  vegetation.  The  raw  mate- 
rials from  which  alcohol  may  be  manufactured  are  found  in  all  parts 
of  the  earth.  It  is  derived  from  any  substance  which  contains  either 
starch  or  sugar,  and  it  can  profitably  be  produced  from  fruits,  grains, 
and  vegetables.  It  may  be  made  from  beets,  sugar-cane,  rice,  barley, 
rye,  corn,  wheat,  or  potatoes,  and  decaying  fruit  or  other  refuse, 
which  could  not  be  utilized  otherwise,  may  be  subjected  to  a  process 
of  distillation  and  alcohol  derived  therefrom. 

Alcohol  differs  materially  from  gasoline,  and  as  it  is  less  volatile 
it  requires  more  heat  to  vaporize  it.  Alcohol  vapor  can  be  compressed 
to  a  greater  degree  than  the  vapors  of  gasoline,  and  as  the  heat  units 
liberated  from  a  fuel  vary  with  the  degree  of  compression  even  though 
alcohol  gives  out  less  heat  when  burned  under  the  same  conditions, 
higher  efficiency  may  be  obtained  by  compressing  the  alcohol  vapor  to 
a  higher  degree.  While  this  substance  has  been  used  for  a  decade  or 
more  abroad,  in  engines  designed  especially  for  its  use,  it  has  not  been 
applied  with  any  degree  of  economy  in  raotors  designed  for  use  with 
gasoline. 

A  motor  constructed  for  use  with  alcohol  must  use  a  higher  degree 
of  compression  than  a  gasoline  motor,  and  a  form  of  carburetor  which 
will  heat  the  mixture  before  it  is  taken  into  the  cylinder  should  be 
used.  An  engine  designed  for  gasoline  will  use  twice  as  much  alcohol 
as  it  does  gasoline  to  develop  the  same  amount  of  energy,  though  in  a 
special  motor  the  same  amount  of  power  will  be  obtained  as  when 
equal  quantities  of  gasoline  are  burned  in  the  conventional  engine. 
One  of  the  disadvantages  of  alcohol  that  is  shared  in  common  with 
kerosene  is  that  it  is  difficult  to  start  an  engine  when  cold,  as  alcohol  is 
not  very  volatile  unless  heated. 

The  amount  of  air  necessary  for  complete  combustion  is  roughly 
estimated  at  one  third  that  needed  with  gasoline.  Twice  the  amount 
of  compression  before  ignition  can  be  used  with  alcohol  vapor.  The 
range  of  explosive  mixture  proportions  of  alcohol  and  air  is  much 
greater  than  that  possible  with  gasoline  and  air.  Various  authorities 
have  stated  that  a  compression  of  one  hundred  and  fifty  pounds  per 
square  inch  is  possible  with  alcohol,  but  it  is  doubtful  if  automobile 
engines  will  ever  be  built  using  such  high  degrees  of  compression. 


236  The  Modern  Gasoline  Automobile 

A  new  process  has  been  recently  developed  with  a  view  of  permit- 
ting one  to  use  alcohol  in  engines  of  present  design  with  no  change 
except  a  special  form  of  vaporizer.  In  this  the  alcohol  vapor  is  passed 
through  calcium  carbide  before  it  enters  the  cylinder.  The  water 
which  is  present  in  commercial  alcohol  and  which  lowers  its  efficiency 
as  a  fuel  is  absorbed  by  the  carbide  and  the  resulting  chemical  action 
liberates  acetylene  gas.  This  is  very  inflammable  and  increases  the  ex- 
plosive value  of  the  alcohol  vapor.  When  the  alcohol-acetylene  combi- 
nation is  used,  to  obtain  the  same  thermal  efficiency  as  with  gasoline 
gas,  it  is  necessary  to  add  water  to  the  alcohol  until  a  solution  con- 
taining seventeen  per  cent  water  and  eighty-three  per  cent  alcohol  is 
obtained. 

This  is  no  great  disadvantage,  as  water  costs  nothing  to  speak  of, 
and  the  increase  in  the  bulk  of  the  fuel  nearly  pays  for  the  carbide. 
It  is  estimated  that  one  pound  of  carbide  is  used  per  gallon  of  liquid. 
As  the  market  price  of  carbide  in  lots  of  one  hundred  pounds  or  more 
is  but  four  to  five  cents  per  pound,  the  only  objection  that  can  be  ad- 
vanced to  the  process  is  the  increased  complication  of  the  vaporizing 
appliance.  The  combination  of  alcohol  and  acetylene  has  proved  effi- 
cient on  motors  employing  compressions  as  low  as  sixty  pounds  to  the 
square  inch  and  running  as  high  as  two  thousand  revolutions  per  min- 
ute, but  when  used  alone  the  slow  burning  qualities  of  alcohol  vapor 
has  made  it  most  efficient  on  slow-speed  high-compression  motors. 

Alcohol  used  for  fuel  purposes  must  be  rendered  unfit  for  drinking 
by  mixing  substances  with  it  which  are  not  palatable,  but  which  do 
flot  interfere  with  its  use  as  a  fuel.  When  so  treated  the  substance 
is  called  denatured  alcohol.  Among  the  substances  which  may  be 
mixed  with  the  ethyl  alcohol  are  wood  alcohol,  benzine,  and  benzol, 
and  various  distillates  of  crude  petroleum.  Chemists  contend  that  it 
is  better  to  use  a  hydrocarbon,  such  as  benzol,  than  the  wood  alcohol, 
as  a  denaturizing  substance,  because  wood  alcohol  tends  to  produce 
acetone  and  other  compounds  which  are  of  corrosive  nature  and  which 
might  corrode  the  metal  parts  of  the  cylinder  which  were  exposed  to 
the  effects  of  a  by-product  resulting  from  incomplete  combustion  of 
such  a  vapor. 

Alcohol  has  the  advantage  in  that  the  fire  risk  is  less  than  with 
gasoline.  The  latter  is  a  more  volatile  liquid  than  alcohol,  and  is 


The  Modern  Gasoline  Automobile  237 

more  dangerous  because  it  evaporates  more  readily.  The  flame  of 
burning  gasoline  is  one  which  radiates  heat  rapidly,  whereas  the  alco- 
hol flame  does  not  radiate  heat  to  such  an  extent.  A  mass  of  burning 
gasoline  will  generate  sufficient  heat  to  set  objects  at  a  considerable 
distance  from  it  on  fire.  The  heat  from  burning  alcohol  goes  upward 
and  exists  mostly  in  the  hot  gases  evolved  by  the  flame.  A  gasoline 
fire  is  spread  by  water,  whereas  burning  alcohol  may  be  extinguished 
by  it.  Gasoline  is  much  lighter  than  water  and  floats  on  its  surface, 
but  alcohol  is  so  nearly  the  same  density  that  it  will  mix  with  the 
water. 

If  one  compares  the  chemical  composition  of  alcohol  and  gasoline 
it  will  be  found  that  it  requires  less  air  to  burn  a  pint  of  alcohol  than 
the  same  amount  of  gasoline.  The  oxygen  contained  in  the  alcohol 
tends  to  make  combustion  better,  and  there  is  practically  no  residue 
left  in  an  engine  burning  alcohol  gas.  The  exhaust  from  any  of  the 
petroleum  distillates  will  smell  strong  and  be  smoky  if  an  excess  of 
fuel  in  proportion  to  air  is  in  the  mixture.  The  burned  products  of 
an  alcohol  mixture  are  not  objectionable  even  if  there  is  an  excess  of 
alcohol.  These  exhaust  gases  besides  being  more  agreeable  to  the 
senses  are  cooler  and  cleaner,  and  as  they  contain  a  smaller  propor- 
tion of  free  carbon  less  of  this  is  deposited  in  the  combustion  chamber 
and  muffler. 

Among  the  conditions  which  are  unfavorable  to  the  use  of  alcohol 
and ,  which  militate  against  its  use  at  the  present  time  can  be  cited 
the  present  types  of  engines  and  carburetors,  and  the  high  price  of 
denatured  alcohol.  While  alcohol  has  not  been  extensively  experi- 
mented with  in  this  country,  because  the  supply  of  gasoline  at  the 
present  time  seems  adequate,  it  is  expected  that,  should  there  be 
a  shortage  of  this  valuable  commodity,  forms  of  vaporizers  will  be 
devised  which  will  permit  the  use  of  alcohol  in  connection  with  pres- 
ent-day forms  of  motors.  Some  authorities  contend  that  alcohol  will 
be  the  fuel  of  the  future,  while  others  believe  that  kerosene  is  more 
adaptable  for  use  in  the  hydrocarbon  motor. 

Solid  Gasoline  as  a  Fuel. — Experiments  are  being  conducted  in 
Europe  with  gasoline  in  the  solid  form,  which  is  said  to  have  some 
advantages  over  the  liquid  fuels.  Solid  gasoline  is  a  transparent 
product  which  is  in  the  form  of  a  jelly,  having  sufficient  consistency 


238  The  Modern  Gasoline  Automobile 

so  that  it  can  be  handled  like  any  other  solid  body.  It  can  be  cut 
into  pieces  just  as  gelatine  can,  and  may  be  conveyed  in  wooden  or 
cardboard  boxes.  If  examined  under  the  microscope  its  structure  is 
similar  to  that  of  a  very  fine  sponge  and  the  theory  is  that  liquid  gaso- 
line is  present  in  the  pores.  Its  properties  in  general  are  the  same  as 
liquid  fuels  as  it  evaporates  very  easily,  and  has  the  same  heat  value. 
When  solid  gasoline  is  heated  it  does  not  melt  under  ordinary  condi- 
tions but  evaporates.  If  it  is  lighted  it  does  not  melt,  but  burns  like 
wood,  and  the  flame  may  be  easily  extinguished  by  covering  with  a 
piece  of  cloth. 

Solidified  gasoline  has  about  eighty  per  cent  the  bulk  of  ordinary 
liquid  gasoline;  whereas  a  gallon  of  liquid  will  occupy  a  space  of  231 
cubic  inches,  the  same  amount  solidified  will  occupy  but  about  185 
cubic  inches.  The  mixture  may  be  easily  obtained,  as  solid  gasoline 
dissolves  in  air  at  ordinary  temperatures  and  yields  a  combustible  gas 
which  may  be  used  in  explosion  motors.  Solid  gasoline  can  be  used 
without  first  converting  it  into  a  liquid  and  a  mixture  of  gasoline 
vapor  and  air  is  formed  by  causing  a  slightly  heated  current  of  air 
to  pass  over  the  surface  of  the  solid  fuel.  It  is  claimed  that  a  very 
good  mixture  is  obtained.'.  Appliances  designed  for  carbureting  solid 
gasoline  utilize  the  exhaust  gases  of  the  motor  as  a  source  of  heat  for 
securing  more  ready  evaporation. 

In  the  experiments  made  abroad  a  special  form  of  carburetor  was 
constructed  to  use  with  solid  fuel.  This  was  composed  of  a  box  with 
a  series  of  pipes  in  its  lower  portion  through  which  the  exhaust  gases 
from  the  engine  were  passed.  A  plate  which  formed  the  bottom  of  the 
fuel  compartment  which  was  28  inches  by  17  inches  wide  by  17  inches 
high  was  placed  on  these  pipes.  The  solid  gasoline  was  not  placed 
directly  on  the  .bottom  of  the  box  but  on  a  wire  mesh  screen  which 
formed  a  false  bottom,  raised  about  two  inches  from  the  true  bottom 
of  the  fuel  compartment.  Four  cakes  of  solid  fuel,  each  seven  inches 
square  by  three  and  one  half  inches  thick,  were  placed  on  the  wire 
screen.  An  air  inlet  was  provided  at  one  end  of  the  box,  the  air  being 
drawn  through  the  space  between  the  bottom  of  the  fuel  box  and 
the  false  bottom  of  wire  mesh  on  which  the  fuel  rested.  As  it  passed 
it  brushed  by  the  gasoline  which  had  been  forced  through  the  mesh 
in  a  form  very  much  the  same  as  icicles  and  which  offered  a  very 


The  Modern  Gasoline  Automobile  239 

large  surface  for  contact.  The  carbureted  air  was  passed  into  a  mix- 
ing box  fitted  with  extra  air  openings  and  from  thence  to  the  inlet 
pipe  of  the  motor.  Four  gauze  screens  were  interposed  between  the 
mixing  and  fuel  chambers  in  order  to  prevent  ignition  of  the  gas  in 
the  fuel  compartment  should  the  motor  back  fire. 

When  the  apparatus  was  cold  the  motor  did  not  run  very  well,  but 
after  it  had  been  running  for  several  minutes  and  the  heating  pipes 
raised  in  temperature  the  engine  worked  very  well.  This  crude  ex- 
periment showed  that  the  ratio  of  weight  of  solid  gasoline  to  the  liquid 
fuel  for  equal  work  done  was  eighty-three  and  five  tenths  per  cent, 
which  meant  that  considered  on  a  basis  of  weight  that  twenty-three 
per  cent  less  solid  fuel  was  needed  to  obtain  the  same  power,  and  that 
eighty-three  and  five  tenths  per  cent  of  solid  gasoline  would  do  as 
much  work  as  one  hundred  per  cent  of  liquid  fuel. 

It  is  not  likely  that  gasoline  in  this  form  will  ever  be  used  to 
any  extent  because  the  carburetor  used  will  have  to  be  very  bulky  and 
very  much  different  in  construction  from  that  used  for  the  liquid. 
The  argument  that  solid  gasoline  is  safer  than  liquid  gasoline  is  not 
borne  out  by  facts  because  it  will  evaporate  quite  readily  and  give  off 
vapors  at  ordinary  temperatures.  It  is  open  to  question  whether  a 
fuel  can  be  handled  easier  in  solid  or  liquid  forms.  It  would  seem  to 
the  writer  that  it  would  be  as  easy  to  pour  fuel  out  of  a  can  directly 
into  a  suitable  container  as  it  would  be  to  handle  it  in  the  form  of 
blocks.  The  expense  of  solidifying  the  liquid  would  probably  be  suf- 
ficiently large  so  that  any  advantages  accruing  would  be  more  than 
balanced  by  disadvantages  of  some  moment.  When  one  considers  that 
all  motor  vehicles  now  in  use  are  fitted  to  burn  liquid  gasoline  the  diffi- 
culty experienced  in  attempting  to  put  the  solid  fuel  on  the  market, 
even  if  it  was  cheaper  than  the  liquid  form,  will  be  readily  understood. 

Principles  of  Carburetion  Outlined. — The  process  of  carburetion  is 
combining  the  volatile  vapors  which  evaporate  from  the  hydrocarbon 
liquids  with  certain  proportions  of  air  to  form  an  inflammable  gas. 
The  quantities  of  air  needed  vary  with  different  liquids  and  some 
mixtures  burn  quicker  than  do  other  combinations  of  air  and  vapor. 
Combustion  is  simply  burning  and  it  may  be  rapid,  moderate,  or 
slow.  Mixtures  of  gasoline  and  air  burn  quickly,  in  fact,  the  combus- 
tion is  so  rapid  that  it  is  instantaneous  and  we  obtain  what  is  com- 


240  The  Modern  Gasoline  Automobile 

monly  termed  an  "  explosion."  Therefore  the  explosion  of  gas  in  the 
automobile  engine  cylinder  which  produces  the  power  is  really  a  com- 
bination of  chemical  elements  which  produce  heat. 

If  the  gasoline  mixture  is  not  properly  proportioned  the  rate  of 
burning  will  vary,  and  if  the  mixture  is  either  too  rich  or  too  weak 
the  power  of  the  explosion  is  reduced  and  the  amount  of  power  applied 
to  the  piston  is  decreased  proportionately.  In  determining  the  proper 
proportions  of  gasoline  and  air,  one  must  take  the  chemical  composi- 
tion of  gasoline  into  account.  The  ordinary  liquid  used  for  fuel  is 
said  to  contain  about  eighty-four  per  cent  carbon  and  sixteen  per  cent 
hydrogen.  Air  is  composed  of  oxygen  and  nitrogen  and  the  former 
has  a  great  affinity,  or  combining  power,  with  the  two  constituents  of 
hydrocarbon  liquids.  Therefore,  what  we  call  an  explosion  is  merely 
an  indication  that  oxygen  in  the  air  has  combined  with  the  carbon  and 
hydrogen  of  the  gasoline. 

In  figuring  the  proper  volume  of  air  to  mix  with  a  given  quantity 
of  fuel,  one  takes  into  account  the  fact  that  one  pound  of  hydrogen 
requires  eight  pounds  of  oxygen  to  burn  it,  and  one  pound  of  carbon 
needs  two  and  one  third  pounds  of  oxygen  to  insure  its  combustion. 
Air  is  composed  of  one  part  of  oxygen  to  three  and  one  half  portions 
of  nitrogen  by  weight.  Therefore  for  each  pound  of  oxygen  one  needs 
to  burn  hydrogen  or  carbon  four  and  one  half  pounds  of  air  must  be 
allowed.  To  insure  combustion  of  one  pound  of  gasoline  which  is  com- 
posed of  hydrogen  and  carbon  we  must  furnish  about  ten  pounds  of  air 
to  burn  the  carbon  and  about  six  pounds  of  air  to  insure  combustion  of 
hydrogen,  the  other  component  of  gasoline.  This  means  that  to  burn 
one  pound  of  gasoline  one  must  provide  about  sixteen  pounds  of  air. 

While  one  does  not  usually  consider  air  as  having  much  weight  at 
a  temperature  of  sixty-two  degrees  Fahrenheit,  about  fourteen  cubic 
feet  of  air  will  weigh  a  pound,  and  to  burn  a  pound  of  gasoline  one 
would  require  about  two  hundred  cubic  feet  of  air.  This  amount  will 
provide  for  combustion  theoretically,  but  it  is  common  practice  to 
allow  twice  this  amount  because  the  element  nitrogen,  which  is  the 
main  constituent  of  air,  is  an  inert  gas  and  instead  of  aiding  combus- 
tion it  acts  as  a  deterrent  of  burning.  In  order  to  be  explosive,  gaso- 
line vapor  must  be  combined  with  definite  quantities  of  air.  Mixtures 
that  are  rich  in  gasoline  ignite  quicker  than  those  which  have  more 


The  Modern  Gasoline  Automobile  241 

air,  but  these  are  only  suitable  when  starting  or  when  running  slowly, 
as  a  rich  mixture  ignites  much  quicker  than  a  weak  mixture.  The 
richer  mixture  of  gasoline  and  air  not  only  burns  quicker  but  produces 
the  most  heat  and  the  most  effective  pressure  in  pounds  per  square 
inch  of  piston  top  area. 

The  amount  of  compression  of  the  charge  before  ignition  also  has 
material  bearing  on  the  force  of  the  explosion.  The  higher  the  degree 
of  compression  the  greater  the  force  exerted  by  the  rapid  combustion 
of  the  gas.  Mixtures  varying  from  one  part  of  gasoline  vapor  to  four 
of  air  to  others  having  one  part  of  gasoline  vapor  to  thirteen  of  air 
can  be  ignited,  but  the  best  results  are  obtained  when  the  proportions 
are  one  to  five  or  one  to  seven,  as  this  mixture  is  the  one  that  will 
produce  the  highest  temperature,  the  quickest  explosion,  and  the 
most  pressure. 

What  a  Carburetor  Should  Do. — While  it  is  apparent  that  the  chief 
function  of  a  carbureting  device  is  to  mix  hydrocarbon  vapors  with 
air  to  secure  mixtures  that  will  burn,  there  are  a  number  of  factors 
which  must  be  considered  before  describing  the  principles  of  vapor- 
izing devices.  Almost  any  device  which  permits  a  current  of  air  to 
pass  over  or  through  a  volatile  liquid  will  produce  a  gas  which  will 
explode  when  compressed  and  ignited  in  the  motor  cylinder.  Modern 
carburetors  are  not  only  called  upon  to  supply  certain  quantities  of  gas, 
but  these  must  deliver  a  mixture  to  the  cylinders  that  is  accurately  pro- 
portioned and  which  will  be  of  proper  composition  at  all  engine  speeds. 

Flexible  control  of  the  engine  is  sought  by  varying  the  engine 
speed  by  regulating  the  supply  of  gas  to  the  cylinders.  The  power 
plant  should  run  from  its  lowest  to  its  highest  speed  without  any 
irregularity  in  torque,  i.  e.,  the  acceleration  should  be  gradual  rather 
than  spasmodic.  As  the  degree  of  compression  will  vary  in  value  with 
the  amount  of  throttle  opening  the  conditions  necessary  to  obtain 
maximum  power  differ  with  varying  engine  speeds.  When  the  throt- 
tle is  barety  opened  the  engine  speed  is  low  and  the  gas  must  be  richer 
in  fuel  than  when  the  throttle  is  wide  open  and  the  engine  speed  high. 

When  an  engine  is  turning  over  slowly  the  compression  has  low 
value  and  the  conditions  are  not  so  favorable  to  rapid  combustion  as 
when  the  compression  is  high.  At  high  engine  speeds  the  gas  velocity 
through  the  intake  piping  is  higher  than  at  low  speeds,  and  regular 


242 


The  Modern  Gasoline  Automobile 


engine  action  is  not  so  apt  to  be  disturbed  by  condensation  of  liquid 
fuel  in  the  manifold  due  to  excessively  rich  mixture  or  a  superabund- 
ance of  liquid  in  the  stream  of  carbureted  air. 


Fig.  132. — Illustrating  Method  of  Storing  Fuel  in  Brush  Runabout,  which 
Permits  Short  and  Direct  Gasoline  Piping. 

Liquid  Fuel  Storage  and  Supply. — The  problem  of  gasoline  stora^ 
and  method  of  supplying  the  carburetor  is  one  that  is  determinec 
solely  by  design  of  the  car.    While  the  object  of  designers  should  be  to 


The  Modern  Gasoline  Automobile 


243 


Tank 


Fig.  133.— Defining  the  Usual  Methods  of  Fuel  Storage  in  Motor  Cars.  A— Oval 
Tank  Back  of  Seat.  B — Round  Tank  at  Rear  of  Chassis,  Common  on  Rac- 
ing Cars.  C — Container  Under  Front  Seat,  the  Conventional  Method.  D — 
Tank  at  Rear  of  Frame,  Underslung,  which  Makes  Pressure-Feed  Neces- 
sary. 


244  The  Modern  Gasoline  Automobile 

supply  the  fuel  to  the  carburetor  by  as  simple  means  as  possible  the 
fuel  supply  system  of  some  cars  is  quite  complex.  The  first  point  to 
consider  is  the  location  of  the  gasoline  tank.  This  depends  upon  the 
amount  of  fuel  needed  and  the  space  available  in  the  car. 

A  very  simple  and  compact  fuel  supply  system  is  shown  at  Fig. 
132,  which  represents  a  plan  view  of  the  motor  compartment  of  the 
Brush  Eunabout.  The  power  plant  in  this  little  car  is  a  single-cylin- 
der engine  of  comparatively  low  power  and  correspondingly  low  fuel 
consumption.  As  it  does  not  require  much  gasoline  to  run  a  small 
engine  one  can  obtain  a  satisfactory  touring  radius  on  one  filling  of 
a  comparatively  small  tank.  In  this  instance  the  fuel  container  is 
suspended  from  the  dashboard  and  is  placed  immediately  back  of  the 
engine  cylinder.  The  carburetor  which  is  carried  as  indicated  is 
joined  to  the  tank  by  a  short  piece  of  copper  tubing.  This  is  the 
simplest  possible  form  of  fuel  supply  system. 

As  the  sizes  of  cars  increase  and  the  power  plant  capacities  aug- 
ment it  is  necessary  to  use  more  fuel,  and  to  obtain  a  satisfactory 
touring  radius  without  frequent  stops  for  filling  the  fuel  tank  it  is 
necessary  to  supply  large  containers.  The  principal  methods  of  carry- 
ing fuel  are  depicted  at  Fig.  133.  At  A  the  tank  is  placed  back  of 
the  seats  and  is  oval  in  shape.  It  can  be  easily  filled,  and  is  carried 
high  enough  above  the  carburetor  so  that  the  fuel  will  run  from  the 
tank  by  gravity.  The  tank  shown  at  B  is  a  cylindrical  form  of  large 
capacity,  and  is  mounted  at  the  extreme  rear  end  of  the  chassis.  This 
member  also  is  mounted  high  enough  above  the  carburetor  so  the  gaso- 
line will  flow  to  it  by  gravity. 

In  some  touring  cars  sufficient  space  is  provided  for  the  recep- 
tion of  a  fair-sized  tank  under  the  front  seats,  as  shown  at  C.  In 
this  the  tank  is  rectangular  and  is  placed  on  suitable  channel  members 
so  it  can  be  supported  on  top  of  the  frame.  When  a  very  powerful 
power  plant  is  fitted,  as  on  touring  cars  of  high  capacity,  it  is  neces- 
sary to  carry  large  quantities  of  gasoline.  With  the  latest  forms  of 
bodies  with  low  seats  it  is  very  difficult  to  find  space  enough  for  the 
placing 'of  an  adequately  large  tank.  The  usual  method  is  depicted 
at  D.  In  this  the  large  fuel  container  is  carried  under  the  frame 
members  at  the  extreme  rear  of  the  chassis.  When  installed  in  this 
manner  it  is  necessary  to  force  fuel  out  of  the  tank  by  air  pressure,  or 


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245 


246 


The  Modern  Gasoline  Automobile 


to  pump  it  because  the  gasoline  tank  is  lower  than  the  carburetor  it 
supplies. 

A  typical  fuel  system  in  which  the  tank  is  placed  under  the  seat, 
as  depicted  at  Fig.  133,,  A,  is  shown  in  detail  at  Fig.  134.  The  carbu- 
retor is  shown  in  section  and  is  attached  to  the  cylinders  by  means  of 
a  "  T  "  form  built-up  manifold.  The  gasoline  tank  is  joined  to  a 
filter  by  a  short  length  of  pipe  and  after  the  liquid  passes  through  the 
filter  it  goes  to  the  carburetor  through  a  suitable  length  of  brass  or 
copper  tubing.  The  filter  is  an  important  little  device  which  removes 
any  water,  sediment,  or  other  foreign  matter  from  the  fuel  before  it 
reaches  the  float  chamber  of  the  carburetor. 


Supply  Chamber 
From  Pump  to  Carburetor 


uerflouf  Pipe  to  Tank   FumP  Plunger 


Pipe  From  Driving  Gear 

Pump  to  Carburetor 


Main  Fuel  Container 


Priming  Pipe 


Hand  Pump 


Fig.  135. — Unconventional  System  in  which  a  Pump  is  Depended  Upon  to  Draw 
Fuel  from  Container  and  Deliver  It  to  Vaporizer. 

The  fuel  system  shown  at  Fig.  135  shows  how  the  gasoline  may  be 
raised  to  the  carburetor  when  the  tank  is  placed  at  the  rear  of  the 
chassis,  as  shown  at  Fig.  133,  D.  A  gear-driven  plunger  pump  takes 
the  fuel  from  the  tank  through  the  suction  pipe  and  delivers  it  to  the 
supply  bowl  of  the  carburetor,  which  it  fills  to  a  height  determined, 
by  an  overflow  tube.  When  the  liquid  in  the  supply  compartment  of 
the  carburetor  exceeds  the  predetermined  level  it  returns  to  the  tank 


The  Modern  Gasoline  Automobile  247 

through  an  overflow  pipe.  Two  pumps  are  provided,  one  worked  by 
the  engine,  the  other  manually  operated.  The  hand  pump  is  used  in 
emergencies,  such  as  for  priming  the  carburetor  or  for  regular  supply 
of  fuel  in  case  of  failure  of  the  main  pump. 

The  most  common  method  of  supplying  gasoline  to  the  carburetor 
when  the  tank  is  carried  so  low  that  the  fuel  will  not  flow  by  its  weight 
is  to  pump  air  or  gas  into  the  supply  tank  and. displace  the  gasoline 
by  its  pressure.  From  the  main  supply  tank  the  fuel  goes  to  a  small 
auxiliary  tank  carried  on  the  dash  of  the  power-plant  compartment. 
A  short  pipe  connects  this  small  container  with  the  carburetor,  and 
as  this  auxiliary  tank  is  higher  than  the  mixing  device  the  fuel  will 
flow  by  gravity.  If  the  gasoline  under  pressure  was  fed  directly  to 
the  carburetor  it  might  result  in  an  oversupply  of  fuel  because  there 
might  exist  pressure  enough  to  force  the  gasoline  into  the  float  cham- 
ber because  the  shut-off  needle  valve  would  not  seat  positively.  The 
auxiliary  tank  is  generally  provided  with  some  form  of  automatic  cut- 
off mechanism,  which  interrupts  the  fuel  supply  when  the  small  con- 
tainer is  nearly  full. 

Early  Vaporizer  Forms. — The  early  types  of  carbureting  devices 
were  very  crude  and  cumbersome,  arid  the  mixture  of  gasoline  vapor 
and  air  was  accomplished  in  three  ways.  The  air  stream  was  passed 
over  the  surface  of  the  liquid  itself,  through  loosely  placed  absorbent 
material  saturated  with  liquid,  or  directly  through  the  fuel.  The  first 
typo  is  known  as  the  surface  carburetor  and  is  now  practically  obso- 
lete. The  second  form  is  called  the  "  wick  "  carburetor  because  the 
air  stream  was  passed  over  or  through  saturated  wicking.  The  third 
form  was  known  as  a  "bubbling"  carburetor.  The  illustrations  at 
Fig.  136  show  the  principles  of  operation  of  two  of  the  earliest  forms 
of  carbureting  devices  that  were  applied  to  change  liquid  gasoline  into 
an  explosive  vapor.  That  shown  at  A  consisted  of  a  large  cylinder 
divided  into  three  parts  by  sheet  metal  partitions.  The  upper  one  was 
utilized  as  a  fuel  compartment,  and  this  was  joined  to  the  main  tank 
by  suitable  piping.  The  center  compartment  was  gas  storage  space, 
and  was  divided  from  the  bottom  chamber  by  two  perforated  baffle 
plates.  The  lower  portion  of  the  cylinder  was  filled  with  wicking. 
This  wicking  was  kept  saturated  with  gasoline  .supplied  from  the  up- 
permost compartment  through  a  pipe  which  directed  the  stream  of 


248 


The  Modern  Gasoline  Automobile 


liquid  against  the  center  of  the  top  baffle  plate.  As  this  member  was 
provided  with  a  large  number  of  holes  the  gasoline  was  divided  into  a 
number  of  fine  streams  and  the  entire  mass  of  wicking  was  saturated. 


Fuel  Regulating 
Needle  Value 


Mixture 
To  Engine 


Drain  Coch  /cfT  ^=r-^=-zz=r^=-jr-— 


Drain  Cock 


Fig.  136. — First  Forms  of  Gasoline  Vaporizers.  A — An  Early  Wick  Carburetor. 
B — Type  in  which  Air  is  Drawn  Through  Fuel  to  Charge  It  with  Explosive 
Vapor. 


When  the  piston  of  the  motor  went  down  on  its  suction  stroke  air 
was  drawn  in  through  the  air  pipe  at  the  bottom  of  the  vaporizing 
device  and  into  the  center  compartment  or  gas  chamber  through  the 
wicking.  In  passing  through  this  saturated  material  the  air  became 
charged  with  gasoline  vapor  and  the  resulting  gas  was  supplied  to 
the  cylinder  through  the  mixture  pipe.  This  method  of  vaporizing  the 
gasoline  produced  mixtures  extremely  rich  in  fuel  and  in  order  to 
burn  these  successfully,  a  simple  form  of  valve  which  permitted  a 
certain*  amount  of  pure  air  to  enter  the  cylinder  and  dilute  the  rich 
charge  was  provided  in  the  mixture  pipe. 

The  carburetor  shown  at  B  is  known  as  the'  "  filtering  "  or  "  bub- 
bling "  type.  This  consists  of  two  chambers :  one  to  hold  the  fuel,  the 


The  Modern  Gasoline  Automobile  249 

other  utilized  as  a  gas  storage  or  mixing  chamber.  A  telescopic  air 
pipe  is  needed,  one  portion  fixed  to  the  tank,  th'e  other,  or  sliding  mem- 
ber, is  carried  by  a  float  which  maintains  a  certain  definite  distance 
between  a  deflector  plate  on  the  pipe  and  the  surface  of  the  liquid. 
The  air  enters  through  the  air  tube  at  the  top,  passes  down  under  the 
surface  of  the  gasoline,  and  is  saturated  with  fuel  particles.  The  rich 
gas  flows  into  the  mixing  chamber  through  screens  of  wire  gauze  and 
after  mixing  with  air  entering  through  the  auxiliary  air  regulator,  the 
gas  passes  from  the  mixing  chamber  to  the  engine  cylinder  through 
suitable  piping. 

While  these  primitive  forms  gave  fairly  good  results  with  the  early 
slow-speed  engines  and  the  high  grade,  or  very  volatile,  gasoline  which 
was  first  used  for  fuel,  they  would  be  entirely  unsuitable  for  present 
forms  of  engines  because  they  would  not  carburate  the  lower  grades 
of  gasoline  which  are  used  to-day,  and  would  not  supply  the  modern 
high-speed  engines  with  gas  of  the  proper  consistency  fast  enough 
even  if  they  did  not  have  to  use  very  volatile  gasoline.  The  form  of 
carburetor  used  at  the  present  time  operates  on  a  different  principle. 
These  devices  are  known  as  "  spraying  carburetors."  The  fuel  is  re- 
duced to  a  spray  by  the  suction  effect  of  the  entering  air  stream  draw- 
ing it  through  a  fine  opening. 

The  advantage  of  this  construction  is  that  a  more  thorough  amal- 
gamation of  the  gasoline  and  air  particles  is  obtained.  "With  the  ear- 
lier types  previously  considered  the  air  would  combine  with  only  the 
more  volatile  elements,  leaving  the  heavier  constituents  in  the  tank. 
As  the  fuel  became  stale  it  was  difficult  to  vaporize  it,  and  it  had  to  be 
drained  off  and  fresh  fuel  provided  before  the  proper  mixture  would 
be  produced.  It  will  be  evident  that  when  the  fuel  is  sprayed  into  the 
air  stream,  all  the  fuel  will  be  used  up  and  the  heavier  portions  of 
the  gasoline  will  be  taken  into  the  cylinder  and  vaporized  just  as  well 
as  the  more  volatile  vapors. 

The  simplest  form  of  spray  carburetor  is  that  shown  at  Fig.  137. 
In  this  the  gasoline  opening  through  which  the  fuel  is  sprayed  into  the 
entering  air  stream  is  closed  by  the  spring-controlled  mushroom  valve 
which  regulates. the  main  air  opening  as  well.  When  the  engine  draws 
in  a  charge  of  air  it  unseats  the  valve  and  at  the  same  time  the  air 
flowing  around  it  is  saturated  with  gasoline  particles  through  the  gaso- 


250 


The  Modern  Gasoline  Automobile 


line  opening.     The  mixture  thus  formed  goes  to  the  engine  througl 
the  mixture  passage.     Two  methods  of  varying  the  fuel  proportioi 
are  provided.     One  of  these  consists  of  a  needle  valve  to  regulate  th( 
amount  of  gasoline,  the  other  is  a  knurled  screw  which  controls  th< 
amount  of  air  by  limiting  the  lift  of  the  jump  valve. 


Jump  Valve 
Adjustment 


Mixture 
Passage 


'ntrance 

I      I  " 


Gasoline  Adjustment 


Fig.  137. — Marine-Type  Mixing  Valve,  by  which  Gasoline  is  Sprayed  into  Air 
Stream  Through  Small  Opening  in  Air- Valve  Seat. 

While  practically  all  modern  motor  cars  use  spraying  carburetors 
having  automatic  fuel  regulation,  in  rare  cases  one  sometimes  finds 
the  earlier  forms  of  carburetors  used  in  improved  and  modified  types. 
The  wick  carburetor,  shown  at  Fig.  138,  is  that  used  on  Lanchester 
(English)  cars.  In  this  the  gasoline  is  taken  from  the  main  tank  by 
means  of  a  pump  and  forced  up  through  the  delivery  pipe  into  a  com- 


The  Modern  Gasoline  Automobile 


251 


partment  in  which  a  number  of  wicks  are  placed.  The  fuel  is  main- 
tained to  a  certain  level  by  means  of  an  overflow  pipe  which  returns 
any  excess  to  the  tank.  The  entering  air  stream  which  is  taken  from 
a  jacket  around  the  exhaust  pipe  and  thoroughly  heated  passes  through 
the  wicks  and  becomes  thoroughly  saturated  with  gasoline.  It  is  well 
mixed  with  the  liquid  vapors  by  passing  through  screens  which  sepa- 
rate the  wick  compartment  from  the  mixture  pipes.  An  auxiliary 
air  pipe  and  valve  are  provided  to  dilute  the  rich  gas  before  it  passes 
into  the  motor  through  the  usual  form  of  inlet  manifold. 


Auxiliary  Air 


Wire  Screen, 


Hot  Air 


-Fuel  Pump 


Tump  Piston 


Fig.  138. — Lanchester  Wick  Feed  Carburetor.     The  Only  Modern  Adaption  of 

Earlier  Forms. 

This  is  the  only  instance  at  the  present  time  to  the  writer's 
knowledge  where  the  earlier  forms  of  carburetors  have  survived. 
One  still  finds  many  vaporizer  valves,  as  shown  at  Fig.  137,  used 
in  marine  installations,  though  there  is  a  growing  tendency  at  the 
present  time  to  use  more  modern  spraying  carburetors  in  this  field 
as  well. 

Development  of  Float-Feed  Carburetor. — The  modern  form  of 
spraying  carburetor  is  provided  with  two  chambers,  one  a  mixing 


252  The  Modern  Gasoline  Automobile 

chamber  through  which  the  air  stream  passes  and  mixes  with  a  gaso- 
line spray,  the  other  a  float  chamber  in  which  a  constant  level  of  fuel 
is  maintained  by  simple  mechanism.  A  jet  or  standpipe  is  used  in  tin 
mixing  chamber  to  spray  the  fuel  through  and  the  object  of  the  float 
is  to  maintain  the  fuel  level  to  such  a  point  that  it  will  not  overflow 
the  jet  when  the  motor  is  not  drawing  in  a  charge  of  gas.  With  the 
simple  forms  of  generator  valve  in  which  the  gasoline  opening  is  con- 
trolled by  the  air  valve,  a  leak  anywhere  in  either  valve  or  valve  seat 
will  allow  the  gasoline  to  flow  continuously  whether  the  engine  is 
drawing  in  a  charge  or  not.  The  liquid  fuel  collects  around  the  air 
opening,  and  when  the  engine  inspires  a  charge  it  is  saturated  with 
gasoline  globules  and  is  excessively  rich.  With  a  float-feed  construc- 
tion, which  maintains  a  constant  level  of  gasoline  at  the  right  height 
in  the  standpipe,  liquid  fuel  will  only  be  supplied  when  drawn  out  of 
the  jet  by  the  suction  effect  of  the  entering  air  stream. 

The  first  form  of  spraying  carburetor  ever  applied  successfully 
was  evolved  by  Maybach  for  use  on  one  of  the  earliest  Daimler  engines. 
The  general  principles  of  operation  of  this  pioneer  float-feed  carbu- 
retor are  shown  at  Fig.  139,  A.  The  mixing  chamber  and  valve  cham- 
ber were  one  and  the  standpipe  or  jet  protruded  into  the  mixing  cham- 
ber. It  was  connected  to  the  float  compartment  by  a  pipe.  The  fuel 
from  the  tank  entered  the  top  of  the  float  compartment  and  the  open- 
ing was  closed  by  a  needle  valve  carried  on  top  of  a  hollow  metal  float. 
When  the  level  of  gasoline  in  the  float  chamber  was  lowered  the  float 
would  fall  and  the  needle  valve  uncover  the  opening.  This  would 
permit  the  gasoline  from  the  tank  to  flow  into  the  float  chamber,  and 
as  the  chamber  filled  the  float  would  rise  until  the  proper  level  had 
been  reached,  under  which  conditions  the  float  would  shut  off  the  gaso- 
line opening.  On  every  suction  stroke  of  the  engine  the  inlet  valve, 
which  was  an  automatic  type,  would  leave  its  seat  and  a  stream  of  air 
would  be  drawn  through  the  air  opening  and  around  the  standpipe  or 
jet.  This  would  cause  the  gasoline  to  spray  out  of  the  tube  and  mix 
with  the  entering  air  stream. 

The^form  shown  at  B  was  a  modification  of  Maybach's  simple 
device  and  was  first  used  on  the  Phoenix-Daimler  engines.  Several 
improvements  are  noted  in  this  device.  First,  the  carburetor  was 
made  one  unit  by  casting  the  float  and  mixing  chambers  together  in- 


253 


254  The  Modern  Gasoline  Automobile 

stead  of  making  them  separate  and  joining  them  by  a  pipe,  as  shown 
at  A.  The  float  construction  was  improved  and  the  gasoline  shut-off 
valve  was  operated  through  leverage  instead  of  heing  directly  fastened 
to  the  float.  The  spray  nozzle  was  surrounded  by  a  choke  tube  which 
concentrated  the  air  stream  around  it  and  made  for  more  rapid  air 
flow  at  low  engine  speeds.  A  conical  piece  was  placed  over  the  jet  to 
break  up  the  entering  spray  into  a  mist  and  insure  more  intimate 
admixture  of  air  and  gasoline.  The  air  opening  was  provided  with 
an  air  cone  which  had  a  shutter  controlling  the  opening  so  that  the 
amount  of  air  entering  could  be  regulated  and  thus  vary  the  mixture 
proportions  within  certain  limits. 

The  form  shown  at  B  has  been  further  improved,  and  the  type 
shown  at  C  is  representative  of  modern  practice.  In  this  the  float 
chamber  and  mixing  chamber  are  concentric.  A  balanced  float 
mechanism  which  insures  steadiness  of  feed  is  used,  the  gasoline  jet 
or  standpipe  is  provided  with  a  needle  valve  to  vary  the  amount  of 
gasoline  supplied  the  mixture  and  two  air  openings  are  provided.  The 
main  air  port  is  at  the  bottom  of  the  vaporizer,  while  an  auxiliary 
air  inlet  is  provided  at  the  side  of  the  mixing  chamber.  There 
are  two  methods  of  controlling  the  mixture  proportions  in  this  form 
of  carburetor.  One  may  regulate  the  gasoline  needle  or  adjust  the 
auxiliary  air  valve.  A  full  description  of  the  modern  types  of  carbu- 
retors will  be  given  in  proper  sequence. 

Elements  of  Carburetor  Design. — The  design  of  the  components  of 
modern  carburetors  differ  largely,  but  most  of  the  modern  mixing 
devices  operate  on  the  same  general  principle.  Certain  features  of 
design  have  been  accepted  generally,  such  as  automatic  mixture  com- 
pensation by  auxiliary  air  valves,  Venturi  type  of  mixing  chamber, 
float  and  mixing  chamber  concentric,  separate  adjustment  for  gaso- 
line and  air,  and  simplicity  of  construction. 

Automatic  compensation  is  made  necessary  because  a  satisfactory 
mixture  must  be  furnished  at  all  engine  speeds  without  the  operator 
constantly  varying  the  fuel  supply  or  air  proportions  to  allow  for 
different  conditions  of  operation  produced  by  varying  speeds.  On 
early  types  of  carburetors  it  was  necessary  to  constantly  vary  the  mix- 
ture proportions  by  working  the  air  shutter  or  fuel  valve  from  the 
Driver's  seat  while  the  vehicle  was  in  motion.  The  aim  was  to  secure 


The  Modern  Gasoline  Automobile  255 

a  mixture  that  was  best  adapted  to  the  conditions  of  operation  then 
present,  and  while  a  skillful  driver  would  manipulate  the  adjustments 
in  a  way  to  deliver  well-proportioned  mixtures  to  the  cylinder  the 
average  operator  did  not  control  the  mixture  exactly  and  the  results 
obtained  did  not  make  for  efficiency. 

The  writer  has  described  the  process  of  carburetion,  and  it  is  evi- 
dent that  the  gas  is  supplied  the  cylinder  by  the  pumping  effect  of 
the  piston.  The  velocity  of  the  entering  gases  depends  upon  engine 
speed,  and  as  the  draught  diminishes  it  will  not  pick  up  as  much  fuel 
as  when  it  is  traveling  at  a  higher  rate.  The  present  type  of  compen- 
sating carburetor  provides  for  a  sufficiently  rapid  flow  of  gas  at  low 
speed  by  constricting  the  mixing-chamber  bore  at  the  spray  nozzle  so 
that  the  gas  speed  will  be  sufficiently  high  when  the  engine  is  pump- 
ing slowly.  The  reduced  diameter  of  the  mixing  chamber  increases 
the  velocity  of  the  gases  because  the  cylinder  must  be  filled  through 
a  smaller  hole  in  a  certain  unit  of  time  than  would  be  the  case  if  the 
bore  were  larger.  Therefore  to  insure  a  full  supply  reaching  the 
cylinder  the  gases  must  pass  the  top  of -the  jet  at  a  high  rate  of 
speed  even  if  the  piston  is  working  slowly.  As  the  opening  is  con- 
stricted not  enough  air  will  be  drawn  in  at  high  speed,  and  it  is  neces- 
sary to  supply  it  through  an  auxiliary  opening  usually  controlled  by 
some  automatic  form  of  valve.  This  can  be  adjusted  to  open  only 
when  the  suction  effect  is  sufficiently  high  to  overcome  the  tension  of 
the  spring  which  holds  the  valve  to  the  seat,  and  this  increased  suc- 
tion effect  obtains  only  at  high  speeds. 

The  Venturi  type  of  mixing  chamber  is  one  which  is  being  widely 
used  at  the  present  time  because  it  has  properties  when  properly  pro- 
portioned of  insuring  high  gas  velocity  at  low  engine  speed.  Special 
care  must  be  taken  in  the  proportions  of  the  air  passage,  as  it  is  neces- 
sary  that  the  area  be  large  enough  to  allow  the  air  stream  to  pass 
through  freely,  yet  at  the  same  time  it  must  be  constricted  to  such 
a  point  that  the  entering  air  stream  will  pass  the  top  of  a  standpipe 
with  sufficient  momentum  to  draw  an  adequate  supply  of  gasoline 
from  the  spray  nozzle.  The  velocity  of  the  air  stream  has  been  vari- 
ously estimated,  but  most  authorities  are  agreed  that  it  should  be  from 
7,000  to  9,000  feet  per  minute  to  insure  picking  up  a  sufficient  amount 
of  liquid  as  it  passes  around  the  spray  nozzle. 


256  The  Modern  Gasoline  Automobile 

If  one  compares  the  carburetors  shown  at  Fig.  139,  B  and  C,  one 
will  find  that  there  may  be  two  distinct  forms.  In  that  shown  at  B 
the  mixing  chamber  is  set  to  one  side  of  the  float  compartment  while 
at  C  the  mixing  chamber  is  concentric  with  the  compartment  in  which 
the  float  is  carried.  The  reason  for  putting  the  mixing  chamber  in 
the  center  of  the  float  is  to  insure  a  constant  level  of  fuel  in  the  stand- 
pipe  regardless  of  the  way  the  carburetor  is  tipped.  With  a  mixing 
device  having  two  chambers,  as  shown  at  B,  the  level  in  the  float 
compartment  and  the  spray  nozzle  will  be  at  the  same  height  only 
when  the  carburetor  is  on  the  level.  In  ascending  or  descending  hills 
either  the  float  chamber  will  be  higher  than  the  mixing  chamber  or  the 
reverse  conditions  obtain. 

At  such  times  that  the  mixing  chamber  is  higher  than  the  float 
container  the  level  of  fuel  in  the  jet  will  be  lower  than  it  should  be. 
If,  at  the  other  hand,  the  float  chamber  is  higher  than  the  jet  the 
fuel  will  overflow  and  the  mixture  will  be  excessively  rich.  With 
a  carburetor  constructed  as  depicted  at  C,  the  spray  nozzle  is  at  a 
central  point  and  the  level  will  not  vary  appreciably  if  the  carburetor 
tilts  one  way  or  the  other.  This  insures  an  even  gas  supply  which  in 
turn  produces  uniform  motor  action.  The  engine  is  not  alternately 
starved  or  flooded,  and  the  mixture  proportions  remain  practically 
the  same. 

In  most  cases  carburetor  designers  believe  it  desirable  to  incorpo- 
rate separate  adjustments  for  gasoline  and  air,  in  order  that  all  tem- 
perature variations  be  compensated  for.  When  an  automatic  air  valve 
is  provided  and  the  spray-nozzle  opening  is  controlled  by  a  needle 
valve  it  is  possible  to  obtain  a  wide  variety  of  mixtures.  With  this 
form  of  construction  two  adjustments  are  provided  which  may  be 
used  separately  or  worked  in  unison  as  conditions  demand.  Gas  mix- 
tures having  proportions  best  adapted  for  low  and  medium  speeds  are 
usually  obtained  by  regulating  the  gasoline  valve,  while  the  best  high- 
speed adjustments  are  secured  by  altering  the  tension  of  the  valve 
spring  which  regulates  the  air  supply  by  restricting  or  increasing  the 
lift  of  the  air  valve. 

Mixing  Chamber  Forms  Commonly  Used. — One  of  the  most  impor- 
tant points  to  be  considered  is  to  provide  a  mixing  chamber  of  such 
form  that  a  direct  passage  will  be  provided  for  the  charge  to  enter  the 


The  Modern  Gasoline  Automobile 


257 


cylinder.  Any  sharp  angles  or  turns  are  apt  to  cause  trouble  because 
the  gas  speed  will  be  retarded  and  an  opportunity  afforded  for  the 
condensation  of  fuel  on  sharp  corners.  A  number  of  representative 
forms  of  mixing  chambers  are  shown  at  Fig.  140.  That  at  A  has  been 
very  popular  and  the  gradual  curve  permits  the  gases  to  flow  easily. 
The  spray  nozzle  is  inserted  at  the  point  where  the  gases  turn  and 
there  is  no  possibility  of  the  entering  air  stream  passing  the  gasoline 
supply  pipe  without  picking  up  some  fuel. 


Mixture,  Outlet 


Mixture  Outlet 


Mixture  Outlet 


Fig.  140.— Showing  Common  Forms  of  Mixing  Chambers  and  Spray  Nozzle 

Locations. 

The  form  of  mixing  chamber  shown  at  B  is  a  preferred  form,  as 
the  passage  for  the  gas  is  direct  to  the  engine  pipes  and  there  is  no 
opportunity  for  the  collection  of  liquids  at  any  sharp  corner.  It  is 
apparent  that  the  diameter  of  the  air-pipe  bore  is  less  around  the 
spray  nozzle  than  it  is  at  the  point  above  the  gasoline  supply  jet. 
This  gives  a  Venturi  effect,  which  is  known  to  produce  automatic  mix- 
ture variations.  The  Venturi  tube  construction  is  valuable  because 
it  insures  high  gas  velocity  at  low  engine  speed. 

The  theory  of  Venturi  tube  or  constricted  air  passage  can  be  easily 
derstood  if  one  considers  the  basic  facts  properly.  When  any  fluid, 
ther  liquid  or  gaseous,  passes  through  a  tube  the  volume  passing  will 
be  the  same  at  all  points  if  the  bore  of  the  pipe  is  constant.  If  gas 
flows  through  a  pipe  having  a  variable  section  the  quantity  of  gas  or 
liquid  flowing  through  the  tube  remains  the  same,  but  the  velocity  is 
inversely  proportional  to  the  area  of  the  section  at  different  points. 
Therefore,  if  the  air  passage  is  contracted  at  a  certain  point  the  speed 
of  the  air  stream  will  be  greater  where  the  area  of  the  opening  is 


258  The  Modern  Gasoline  Automobile 

less.  As  will  be  evident  the  air  passage  is  usually  constricted  at  the 
spray  nozzle  for  reasons  previously  outlined. 

In  the  form  of  mixing  chamber  shown  at  A  no  auxiliary  air  device 
is  provided,  but  in  that  depicted  at  B  an  auxiliary  air  valve  is  pro- 
vided at  one  side  of  the  mixing  chamber.  The  form  of  air  passage 
outlined  at  C  is  not  as  satisfactory  as  the  simpler  forms,  which  pro- 
vide for  more  direct  gas  flow.  In  this  the  entering  air  is  forced  to 
turn  a  sharp  corner,  and  the  resistance  this  offers  will  seriously  retard 
the  speed  of  the  entering  air  stream.  The  form  of  mixing  chamber 
outlined  at  B  is  that  commonly  used. 

Problem  of  Float-Bowl  Design. — Next  in  importance  to  the  mixing 
chamber  form  is  the  problem  of  float-chamber  design,  and  the  mech- 
anism which  regulates  the  height  of  the  fuel  in  the  spray  nozzle  should 
be  as  simple  and  as  positive  in  action  as  possible.  The  float  and  nee- 
dle should  be  so  arranged  that  the  gasoline  will  be  regulated  in  such 
a  manner  that  as  soon  as  the  proper  level  is  reached  the  gasoline  ori- 
fice should  be  shut  off  positively.  If  the  mechanism  is  made  simple  it 
is  not  so  likely  to  get  out  of  order  as  when  more  complicated  methods 
of  valve  operation  are  provided. 

The  floats  are  made  in  two  forms.  They  may  be  a  hollow  sheet- 
metal  construction,  or  cork.  When  a  hollow  metal  float  is  employed 
care  is  taken  to  insure  that  it  will  be  absolutely  tight  and  that  fuel 
cannot  enter  its  interior.  Cork  floats  are  usually  coated  with  a  shellac 
varnish  to  minimize  the  danger  of  the  cork  absorbing  fuel.  The  metal 
float  is  more  expensive  than  the  cork,  and  if  it  leaks  it  will  fill  with 
liquid  and  cause  the  carburetor  to  flood.  The  cork  float  may  absorb 
sufficient  fuel  to  change  its  weight  enough  so  that  the  gasoline  level 
will  be  too  high.  It  is  also  contended  that  particles  may  become  de- 
tached from  the  cork  float  and  enter  the  passage  leading  from  the 
float  compartment  to  the  spray  nozzle  and  clogging  it  or  passing  on 
further  and  constricting  the  bore  of  the  jet. 

The  simplest  form  of  float  mechanism  is  depicted  at  Fig.  141,  A. 
Here  the  float  is  pivoted  at  one  end  and  carries  the  needle  at  the  other. 
The  needle  closes  the  gasoline  orifice  when  the  level  of  fuel  is  at  tha 
right  height.  As  soon  as  the  level  falls  the  float  drops  and  the  needle 
valve  leaves  its  seat  and  permits  gasoline  to  enter.  When  sufficient 
has  been  admitted  to  restore  the  level  to  the  proper  point  the  float 


The  Modern  Gasoline  Automobile 


259 


rises  and  tho  gasoline  opening  is  stopped  up  by  the  needle.  The  form 
shown  at  B  is  a  modification  of  the  simpler  construction  outlined  at 
A.  In  this  the  fuel-supply  needle  is  carried  at  the  center  of  the  cir- 
cular float  instead  of  at  one  end.  The  disadvantage  of  these  simple 
forms  in  which  the  gasoline  enters  at  the  top  of  the  float  chamber  is 


Gasoline  Inlet 
Needle 


Ltuer 


Needle 


Gasoline  Entrance 


Gasoline  Inlet 


Weight 


Lever 
Gasoline  Inlet 


Needle 


Fig.  141.— Types  of  Float  Chambers  in  Common  Use  Denning  Various  Methods 
of  Controlling  Fuel-Supply  Valve. 

thai  the  weight  of  the  entering  fuel  which  falls  on  the  float's  surface 
I » re  \ents  the  float  from  rising  as  quickly  as  it  should,  and  the  fuel 
supply  is  not  cut  off  until  the  level  is  somewhat  higher  than  it 
should  be. 

The  form  shown  at  C  utilizes  a  hollow  metal  float  which  operates 
the  shut-off  needle  through  toggle  linkage.  As  the  float  falls  the  lev- 
ers reverse  the  movement  and  the  needle  valve  is  lifted,  this  admitting 


260  The  Modern  Gasoline  Automobile 

fuel  through  the  hole  at  the  bottom  of  the  float  chamber.  A  balanced 
float  construction  is  outlined  at  D.  The  needle-valve  stem  carries  a 
weight  which  tends  to  keep  it  seated  in  a  positive  manner,  and  with 
this  form  of  weighted  valve  one  is  not  apt  to  have  the  erratic  fuel 
supply  that  might  be  caused  by  vibration  of  power  plant  or  road  on 
the  simpler  forms  depicted  at  A  and  B.  The  float  is  not  balanced  by 
the  weight  unless  the  level  is  at  the  proper  height,  and  when  the  fuel 
level  falls  the  weight  of  the  float  which  is  increased  in  value  by  the 
system  of  leverage  raises  the  needle  and  weight.  As  in  the  previous 
case,  shown  at  C,  the  function  of  the  leverage  is  to  reverse  the  direc- 
tion of  movement.  That  is,  the  needle  valve  is  raised  from  its  seat 
when  the  float  falls  and  is  seated  when  the  float  rises. 

Gasoline  Spray  Nozzle  Form  Important. — At  Fig.  142  various  forms 
of  spray  nozzles  and  auxiliary  air  valves  are  depicted.  The  simplest 
form  is  presented  at  A,  this  consisting  of  a  standpipe  having  a  single 
small  hole  at  the  top  through  which  the  fuel  is  discharged  in  a  solid 
stream  in  much  the  same  manner  as  water  through  a  hose.  On  some 
foreign  carburetors  the  standpipe  is  provided  with  a  tapered  plug,  hav- 
ing series  of  grooves  cut, in  its  surface  for  the  passage  of  fuel,  as  shown 
at  B.  The  advantage  of  this  construction  is  that  the  gasoline  is  atom- 
ized and  is  discharged  in  a  number  of  fine  streams  instead  of  the 
coarser  single  stream.  When  the  gasoline  is  discharged  in  a  form  of 
a  mist  it  produces  a  much  better  mixture  than  when  ejected  in  a  single 
stream  which  must  be  broken  up  and  divided  into  fine  particles  before 
it  will  form  a  homogeneous  mixture.  The  disadvantage  of  the  grooved 
plug  is  that  the  fine  passages  are  apt  to  become  clogged  from  very 
small  particles  of  foreign  matter  in  the  fuel.  In  fact,  pieces  of  dirt 
which  would  pass  out  with  the  stream  of  gasoline  from  the  nozzle 
shown  at  A  will  clog  the  fine  passages  of  the  plug  shown  at  B. 

The  amount  of  fuel  delivered  through  the  simple  standpipe  is 
regulated  by  the  size  of  the  hole,  while  the  quantities  of  liquid  sprayed 
from  the  nozzle  shown  at  B  can  be  varied  to  obtain  different  mixtures 
by  changing  the  number  of  grooves  in  the  plug  seat.  The  spray  noz- 
zles illustrated  at  C  and  D  are  forms  in  which  the  gasoline  supply  is? 
regulated  by  a  needle  valve,  that  at  C  using  an  overhead  valve,  while 
that  at  D  has  the  needle  valve  adjusted  from  the  bottom.  The  former 
construction  is  preferred  when  it  is  possible  to  apply  it  because  it 


The  Modern  Gasoline  Automobile 


261 


has  a  tendency  to  divide  the  stream  of  fuel  into  a  spray  or  mist  which 
is  more  easily  vaporized. 

The  spray  nozzles  shown  at  C  and  D  are  used  more  often  than 
those  depicted  at  A  and  B  because  of  the  ease  with  which  the  gasoline 


Grooved  Plug 


Needle  Value 


Fig.  142. — Spray  Nozzle  Forms  and  Methods  of  Supplying  Auxiliary  Air  to 
Modern  Carburetors. 

proportions  may  be  varied  by  screwing  the  needle  in  or  out  of  its  seat, 
thus  reducing  the  size  of  the  opening  when  one  desires  to  diminish 
the  amount  of  fuel  or  screwing  it  out  and  allowing  more  fuel  to  pass 
when  richer  mixtures  are  desired. 

Typical  Auxiliary  Air  Valve  Forms. — Considerable  difference  of 
opinion  exists  in  air  valve  construction  as  well,  and  many  methods  of 
admitting  auxiliary  air  are  used.  The  ordinary  mushroom  or  poppet 


262 


The  Modern  Gasoline  Automobile 


valves  depicted  at  Fig.  142,  E  and  F,  are  more  widely  applied.  The 
former  is  a  flat  seat  type  kept  seated  by  a  compression  spring  while 
that  at  F  is  the  ordinary  form  of  automatic  valve  having  a  bevel  seat, 
The  disadvantage  of  a  poppet  valve  is  that  its  action  is  not  regular, 
and  it  is  apt  to  chatter  or  vibrate  rapidly  if  the  suction  is  not  constant. 

Ball  and  reed  valves  have  been  applied  on  many  forms  of  carbu- 
retors, and  it  is  claimed  for  these  that  they  will  provide  an  increasing 
supply  of  air  as  the  engine  speed  augments  without  chattering  or 
fluctuation.  When  a  series  of  openings  are  provided  instead  of  one 
large  port  and  each  of  the  smaller  holes  is  regulated  by  an  individual 
reed  or  ball  it  is  possible  to  so  vary  the  strength  of  the  reeds,  or  the 
weight  of  the  ball,  that  the  air  supply  will  be  progressive. 

When  poppet  valves  are  used  it  is  customary  to  make  these  of 
leather  or  fiber  so  that  they  will  not  be  noisy  when  they  seat.  The 
method  defined  at  Gr  is  one  in  which  reeds  are  used,  three  being  pro- 
vided, so  graduated  in  strength  that  one  alone  opens  at  medium  speed, 
then  the  other  two  leave  their  seats  progressively  as  the  engine  speed 
augments  and  the  suction  effect  becomes  greater.  The  various  forms 
of  spray  nozzles  and  auxiliary  valves  commonly  used  will  be  further 
described  in  connection  with  the  features  of  the  leading  types  of 
vaporizers. 

Methods  of  Gas-Supply  Regulation. — The  methods  of  regulating 
the  amount  of  gas  supplied  the  cylinder  vary  to  some  extent,  though 
the  general  system  is  to  introduce  some  form  of  butterfly  or  shutter 
valve  in  the  mixture  pipe  between  the  mixing  chamber  and  the  valve 
chamber.  These  valves  are  operated  by  rod  connection  to  hand  lever 
placed  on  top  of  the  steering  post  or  accelerator  pedal  on  foot  boards, 
and  the  amount  of  gas  passing  from  the  carburetor  into  the  cylinder 
depends  upon  the  amount  of  opening  provided  by  the  valve.  When  it 
is  fully  opened  the  gas  may  fill  the  cylinders  easily,  though  as  its 
position  changes  the  area  of  the  mixture  passage  is  gradually  decreased 
and  the  amount  of  gas  passing  through  reduced. 

In  some  cases  the  hand  throttle  is  supplemented  by  an -automatic 
go vernor- which  is  designed  to  shut  off  tho  gas  supply  should  the  engine 
speed  increase  beyond  a  certain  predetermined  point.  A  carburetor 
fitted  with  both  hand-operated  throtilc  mid  shutter  actuated  by  a 
governor  from  the  engine  is  shown  at  Fig.  143.  The  hand  throttle 


The  Afodern  Gasoline  Automobile 


263 


is  a  simple  disk  valve  attached  to  a  stem  passing  through  the  mixture 
pipe  tit  a  central  point.  When  in  the  position  shown  the  passage  is 
fully  opened.  The  governor  throttle  is  a  shutter  valve  placed  in  a 
special  pocket  ahove  the  hand-operated  disk.  It  is  worked  by  lever 
and  rod  connection  by  a  centrifugal  governor. 

The  governor  consists  of  two  weights  pivoted  in  such  a  manner 
that  they  lie  close  to  the  governor  shaft  when  engine  speeds  are  low. 


Governor  Throttle 
Hand  Throttle 


Fig.  143.— Showing  Method  of  Regulating  Fuel  Mixture  Supplied  the  Cylinders 
by  Means  of  Centrifugal  Governor,  which  Automatically  Reduces  the 
Quantity  when  Engine  Speed  Exceeds  a  Certain  Predetermined  Limit. 

As  the  speed  of  the  governor  shaft  increases  the  weights  tend  to  fly  out 
from  center  due  to  centrifugal  force,  and  as  they  are  thrown  out  they 
pull  a  sliding  collar  back  against  a  spring.  The  sliding  collar  actuates 
a  lever  which  closes  the  governor-throttle  valve  by  the  rod  connecting 
it  to  the  governor.  The  governor  is  driven  from  the  engin'e  by  some 
form  of  driving  gear,  or  it  may  be  located  on  the  cam  shaft.  The 
amount  the  weights  fly  out  is  regulated  by  the  spring,  and  as  its  ten- 
sion is  increased  it  will  take  a  higher  engine  speed  to  throw  the 
weights  out  sufficiently  to  close  the  governor  throttle.  When  the  spring 
is  weakened  the  governor  weights  fly  out  at  lower  speeds  and  the  gov- 
ernor throttle  is  closed  sooner. 

Such  a  device  is  useful  in  preventing  racing  of  the  engine  under 
certain  conditions.    For  instance,  if  the  car  was  climbing  a  hill  on  one 


264  The  Modern  Gasoline  Automobile 

of  the  lower  gear  ratios  which  would  permit  the  engine  to  run  quite 
fast  and  the  clutch  pedal  was  depressed  so  that  the  drive  would  be 
momentarily  interrupted,  the  tendency  of  the  engine,  thus  relieved  of 
its  load,  would  be  to  run  at  an  extremely  high  rate  of  speed.  If  the 
operator  was  fully  occupied  in  steering  and  shifting  gears  he  could  not 
regulate  the  hand-throttle  valve  and  the  result  would  be  that  the 
engine  would  run  dangerously  fast.  When  a  governor  is  fitted,  as 
soon  as  the  engine  speed  tends  to  become  excessive  the  weights  fly  out 
and  the  supply  of  gas  is  diminished  automatically. 

A  governor  is  also  useful  on  commercial  cars  where  it  is  desired 
to  keep  the  vehicle  speed  within  certain  limits.  As  speed  is  directly 
dependent  upon  the  number  of  engine  revolutions,  the  governor  can 
be  set  in  such  a  way  that  the  engine  will  run  up  to  a  certain  point  and 
no  faster.  Governors  are  not  so  widely  used  at  the  present  time  as 
they  were  in  the  past,  owing  to  improvements  in  carburetor  control 
devices.  All  governors  do  not  operate  on  the  centrifugal  principle. 
Some  are  hydraulic,  others  are  worked  by  compressed  air.  The  fly 
ball  governor  described  is  the  most  common,  and  as  it  shows  clearly 
the  principle  of  action  and  utility  of  such  devices  there  is  no  need  of 
considering  the  other  forms  which  are  so  rarely  found. 

Construction  of  Modern  Carburetors. — As  the  gasoline  used  in  for- 
eign countries  is  an  imported  product  and  is  therefore  more  costly 
than  it  is  in  the  United  States,  the  foreign  carburetors  have  been  de- 
veloped with  a  main  object  in  view  of  securing  maximum  fuel  effi- 
ciency, and  minimum  fuel  consumption  is  sought  rather  than  greater 
flexibility.  In  this  country  conditions  have  been  such  that  the  eco- 
nomical aspect  has  been  somewhat  neglected  because  at  the  present 
time  the  cost  of  fuel  is  really  one  of  the  smallest  items  to  be  consid- 
ered in  operating  the  average  touring  car.  Carburetors  of  domestic 
development  are  not  so  susceptible  to  derangement  as  those  of  foreign 
derivation,  but  they  are  not  so  efficient  and  consume  more  fuel.  The 
varying  conditions  to  be  met  in  the  effort  made  to  secure  power,  gaso- 
line economy,  and  flexibility  have  resulted  in  a  wide  variety  of  instru- 
ments. It  is  apparent  that  these  must  operate  on  definite  principles 
common  to  all,  but  at  the  same  time  considerable  difference  of  opin- 
ion exists  among  designers  and  details  of  construction  differ  in  almost 
all  forms. 


The  Modern  Gasoline  Automobile 


265 


The  Schebler  Model  "  E  "  carburetor  is  a  concentric  float  type,  and 
is  one  of  the  simplest  and  most  satisfactory  of  the  many  forms  that 
have  received  wide  application.  The  primary  air  inlet  is  through  an 
air  bend  at  the  bottom  of  the  carburetor,  as  shown  at  Fig.  144,  and 
an  auxiliary  air  inlet  controlled  by  the  usual  form  of  poppet  valve  is 


Air  Value  Spring 
Leather  Air  Value  Di 


Auxiliary  Air  Port 
Throttle  Leuer^-A 

11 

Throttle  Disc 


Gas  Outlet 


Lock  Spring 
Lock  Nut 

Air  Value  Adjusting 
Screw 


Float  Value 


Primary  Air  Inlet 
Air  Bend 


Reversible  Union  Ell 


Needle  Value  Packing  Nu 
Gasoline  Adjusting  Needle  Valve 


Fig.  144.— Schebler  Carburetor  Construction  Outlined.      This  Is  One  of  the 
Simplest  Forms  that  Have  Been  Used  Extensively. 

provided  at  the  top  of  the  mixing  chamber.  The  spraying  nozzle  is 
inserted  at  an  angle  and  the  amount  of  fuel  sprayed  into  the  mixture 
is  regulated  by  a  gasoline-adjusting  needle.  The  gasoline  shut-off 
valve  in  the  float  chamber  is  operated  through  a  lever  fulcrumed  at  its 
central  point,  the  float  being  attached  at  one  end  while  the  float- 
control  valve  is  carried  at  the  other.  An  upward  movement  of  the 


266 


The  Modern  Gasoline  Automobile 


float  closes  the  valve,  which  is  opened  as  the  float  falls.  The  gasoline 
needle  is  depended  upon  for  varying  the  mixture  for  low  speed,  while 
the  auxiliary  air  valve  takes  care  of  high-speed  mixture  adjustments, 
The  Kingston  device,  which  is  shown  in  section  at  Fig.  145  with 
important  parts  clearly  depicted,  is  similar  in  principle  to  that  pre- 


Needle  Value  Lock  Screw 
Throttle  Lever 


asoline  Adjusting  Screw 
Venturt  Tube 


Rail  Seat  Cage 
Balls 


uxiliaryAir  Ports 

Float  Value  Cap 


Cork  Float 
Float  Chamber 

Spraying  Nozzle*^**  Bend 
Needle  Valve 


Float  Valve 
Float  Hinge 

Pipe  Connection 
Gasoline  Inlet 


Fig.  145. — Kingston  Automatic  Carburetor  Admits  Auxiliary  Air  Through  Ball- 
Controlled  Ports  at  Side  of  Mixing  Chamber. 

viously  described,  inasmuch  as  it  has  a  concentric  float  and  mixing 
chamber  and  a  lever-control  float  valve.  The  main  air  opening  is 
through  an  air  bend  at  the  bottom  of  the  carburetor,  and  the  mixing 
chamber  is  constricted  at  the  top  of  the  spray  nozzle  to  produce  a 
Venturi  tube  effect.  The  auxiliary  air  ports  are  controlled  by  a  series 
of  balls,  of  varying  weight  which  open  progressively  as  the  motor  suc- 
tion increases.  Fuel  reflation  is  by  an  overhead  needle  valve,  while 
the  amount  of  mixture  passing  to  the  cylinders  through  the  gas  outlet 
is  regulated  by  a  simple  throttle  disk  which  operates  on  the  same 


The  Modern  Gasoline  Automobile 


267 


principle  as  the  damper  of  a  stove  pipe.  This  differs  from  the  throttle 
arrangement  of  the  carburetor  shown  at  Fig.  144,  as  that  member  is 
composed  of  a  movable  plate  which  has  an  up-and-down  motion  instead 
of  the  oscillating  motion  of  the  damper  form.  The  throttle  of  the 
former  type  is  known  as  a  "  butterfly  valve/'  while  that  shown  at  Fig. 
Ill  is  a  simple  shutter  type. 


Gas  Outlet 


Throttle  Disc 
Spraying  Nozzle 


Float  Valve  Cap 


Counter  Weight 


Float  Value 


Air  Valve 
\AirValueSpring 


ir  Value  Spring 
jfHllll  Adjusting  Screw 


Air  Value  Lift  Adjustment 
—Primary  Air  Inlet 


Gasoline  Inlet 
Float  Hinge 
Metal  Float 


Needle  Value  Packing  Nut 
Gasoline  Adjusting  Needle  Value 


Fig.  146.— Holley  Carburetor  with  Spring-Controlled  Poppet  Valve  to  Regulate 
Auxiliary  Air  Passage. 

Another  simple  type  of  vaporizer  which  has  given  very  good  re- 
sulis  in  practice  is  shown  in  section  at  Fig.  146.  This  is  a  concentric 
float  design  having  the  auxiliary  air  port  closed  by  a  flat-seated  valve. 


268  The  Modern  Gasoline  Automobile 

The  gasoline  control  member  is  a  balanced  valve  having  a  counter- 
weight which  tends  to  prevent  vibration.  The  mixture  proportions  ai 
regulated  by  a  gasoline-adjusting  needle  valve  at  the  bottom  of  tl 
carburetor  and  the  air  valve  spring  tension  adjustment.  The  mi: 
ture  delivered  to  the  cylinders  of  the  motor  is  regulated  by  a  simp] 
form  of  throttle  disk. 

A  later  and  improved  form  of  Holley  Carburetor  is  shown  in  sec- 
tion at  Fig.  147.  In  this  the  main  air  enters  through  a  pipe  at  the 
side  of  the  carburetor  which  communicates  with  an  annular  chamber 
surrounding  the  mixing  tube.  The  gasoline  collects  in  a  small  basin- 
at  the  top  of  the  partition  separating  the  float  bowl  from  the  mixing 
tube.  The  gasoline  supply  is  regulated  by  the  usual  form  of  needle 
valve  at  the  bottom  of  the  float  bowl.  In  this  carburetor  the  only 
moving  part  is  the  float  and  the  auxiliary  air  valve  or  auxiliary  air 
openings  have  been  eliminated  by  a  special  construction  of  the  spray 
nozzle.  v 

Eeferring  to  the  lettering  on  the  drawing  the  action  of  this  form 
of  carburetor  can  be  easily  understood.  The  fuel  from  the  tank  enters 
the  float  chamber  A  I  to  the  gasoline  filter  screen  B,  and  the  level 
is  regulated  by  the  inlet  valve  C,  which  is  actuated  by  the  usual  float 
and  lever  combination  D.  When  the  motor  is  not  running  the  level 
is  halfway  up  the  cup  E  and  submerges  the  lower  end  of  the  low-speed 
tube  F.  When  starting  the  engine  the  throttle  G  is  nearly  closed 
and  gasoline  and  air  are  drawn  through  F  with  very  high  velocity 
owing  to  the  degree  of  suction,  thus  forming  a  rich  mixture  and  mak- 
ing starting  easy.  The  tube  F  continues  to  supply  the  motor  at  low 
speeds,  but  as  the  throttle  valve  opens  the  small  tube  gradually 
emerges  into  the  larger  one  and  all  the  mixture  supplied  at  motor 
speeds  above  300  R.  P.  M.  passes  through  the  main  mixing  tube  H. 

The  spray  nozzle  I  has  a  slot  J  which  is  supplied  by  two  separate 
channels,  the  series  of  holes  M  and  the  plug  L,  the  latter  having  a 
limited  hole.  At  low  engine  speeds  both  operate,  M  predominating, 
but  assthe  speed  increases  the  fuel  level  automatically  drops,  because 
the  needle  C  must  lift  higher  with  the  increase  in  amount  furnished. 
The  leverage  is  about  three  to  one,  so  that  the  float  drop  is  three  times 
the  movement  of  the  needle,  and  the  holes  M  are  uncovered  to  the 
atmosphere  above  the  fuel  surface,  which  passes  through  the  slot  J 


The  Modern  Gasoline  Automobile 


269 


and  maintains  the  uniformity  of  the  mixture.  The  gasoline  feed  at 
low  speeds  is  adjusted  by  the  size  of  the  plug  opening  0,  extreme 
high  speeds  by  the  area  of  the  orifice  in  plug  L,  and  the  intermediate 


Fig.  147.— Latest  Model  of  Holley  Carburetor  with  By-pass  Tube  to  Provide 

Easier  Starting. 


ratios  through  the  automatic  action  provided  by  the  series  of  holes  M, 
the  slot  J  and  the  nozzle  I,  and  the  adjusting  needle.    The  advantages 


270 


The. Modern  Gasoline  Automobile 


claimed  by  the  designer  are :  permanent  adjustment,  positive  starting, 
due  to  high  vacuum  and  air  velocity  directly  applied  to  the  source  oi 
fuel  supply;  positive  action  at  low  and  idling  speed  due  to  rich  mix- 
ture; greater  economy  and  rapid  acceleration,  owing  to  more  homo- 
geneous and  better-proportioned  vaporization.  A  richer  mixture 
automatically  obtained  for  hill  climbing  and  hard  pulling  because  th( 
fuel  level  rises  with  slower  motor  speed  and  feeds  the  spray  nozzk 
through  two  channels  instead  of  one. 

A  typical  foreign  type  of  simple  carburetor  is  shown  at  Fig.  148, 
this  being  the  vaporizing  device  used  on  Mercedes  cars.    This  is  a  floal 


Fig.  148. — Mercedes  Carburetor,  which  Has  Retained  Substantially  the  Same 
Form  as  when  First  Designed  Nearly  a  Decade  Ago. 

feed  type  having  a  float  chamber  carried  at  one  side  of  the  mixing 
chamber.  The  spray  nozzle  is  a  simple  type  which  extends  in  a  tube 
having  one  end  open  to  the  main  supply  pipe  and  the  other  to  the 


The  Modern  Gasoline  Automobile 


271 


annular  chamber  through  which  the  air  is  inspired.  The  mixture 
supply  is  regulated  by  a  sliding  throttle  valve  K,  which  also  provides 
the  auxiliary  air  in  increasing  proportions  as  the  amount  supplied  the 
cylinders  is  increased.  The  only  way  the  gasoline  proportions  may  be 
altered  is  by  varying  the  spray  nozzle  or  changing  the  level  of  the  float. 


Fig.  149.— Sectional  View  of  Chapin  Carburetor,  which  Has  Mechanical  Control 
of  Auxiliary  Air  Opening  and  Spray  Nozzle  Needle. 

The  carburetor  shown  in  section  at  Fig.  149  is  a  type  which  has  no 
auxiliary  air  valve,  the  auxiliary  air  opening  being  controlled  by  a 
valve  which  is  directly  actuated  by  a  mechanical  connection  between 


272 


The  Modern  Gasoline  Automobile 


the  throttle  disk  so  that  as  the  throttle  is  opened  more  air  is  allowec 
to  flow  through  the  auxiliary  opening.     The  main  air  enters  througl 
the  air  bend  at  the  bottom  and  passes  around  the  spray  nozzle,  whk 
is  placed  at  the  point  of  least  area  of  the  air  tube.     The  amount  of 
gasoline  supplied  the  mixture  is  regulated  by  the  fuel  -needle  F,  and 
this  is  raised  by  leverage  from  the  throttle  so  that  more  fuel  is  sprayed 
into  the  mixture  at  higher  motor  speed.     In  other  respects  the  carbu- 
retor is  a  conventional  construction. 

The  Excelsior  carburetor,  which  is  shown  in  section  at  Fig.  150, 
has  several  distinctive  features,  one  of  these  being  the  floating  ball 


Needle  Value 


Inspection 

Opening 

Cap 


Spiral  Rack 


Index 


Value 


Mixing  Chamber 


Air  Value 
Spring 

Pinion 


Large  Gear 


Air  Value  Spring 
Tension  Adjustment 


B 


Fig.  150. — Sectional  View  of  Excelsior  Carburetor.  A — Side  Section  Depicting 
Floating  Ball  Controlling  Mixture  Passage.  B— Showing  Peculiar  Air  Valve 
Spring  and  Geared  Control  of  Air  Valve  Stem. 

in  the  air  tube  and  others  exist  in  the  peculiar  form  of  auxiliary  air- 
valve  mechanism.  It  is  claimed  that  the  ball  which  rests  against  the 
pin  D,  shown  in  sectional  view  A,  constricts  the  bore  of  the  air  tube 
at  low  >speed  so  that  the  velocity  of  the  air  passing  the  spray  nozzle  is 
sufficiently  high  to  insure  taking  up  the  proper  amount  of  gasoline, 
but  no  more  than  that  required  to  insure  positive  action  of  the  engine. 
At  highest  engine  speed  the  floating  ball  is  drawn  up  against  the  stop 


The  Modern  Gasoline  Automobile  273 

pin  D?  and  the  air  passage  is  practically  free  from  any  interruption. 
Under  this  condition  the  Venturi  tube  is  permitted  to  exercise  its 
function  and  a  correspondingly  large  amount  of  gasoline  is  drawn 
from  the  spray  nozzle.  It  is  claimed  that  the  floating  ball  controls  the 
mixture  automatically  in  that  it  permits  the  motor  to  get  just  the 
amount  of  gasoline  it  needs  and  thus  conduces  to  economy. 

The  auxiliary  air  valve  is  controlled  by  a  clock  spring  the  tension 
of  which  is  multiplied  by  a  series  of  gears.  The  tension  is  extremely 
light  when  the  valve  is  closed  and  increases  as  the  valve  opens.  It  is 
claimed  that  this  form  of  spring  cannot  vary  and  that  it  will  main- 
tain its  tension  indefinitely.  The  air  valve  stem  is  provided  with  a 
spiral  rack  at  one  end  which  meshes  with  a  small  pinion  controlled  by 
the  air  valve  spring.  Any  movement  of  the  light  air  valve  is  multi- 
plied many  times  by  the  gearing  so  that  the  spring  tension  may  be 
comparatively  light. 

The  carburetor  is  a  concentric  float  type  and  with  the  exception 
of  the  floating  ball  in  the  air  tube  and  the  peculiar  form  of  air-valve 
mechanism  it  does  not  differ  from  conventional  practice.  Referring  to 
sectional  view  A  at  Fig.  150  the  principle  of  action  can  be  easily  un- 
derstood. The  fuel  enters  the  float  chamber  F  through  connection  U 
and  a  constant  level  is  maintained  by  the  float  valve,  which  is  directly 
actuated  by  the  hollow  metal  float  W.  The  primary  air  enters  at  P 
and  is  drawn  by  motor  suction  past  the  spray  nozzle  M  located  in  the 
restricted  portion  of  the  Venturi  tube.  The  amount  of  gasoline  ad- 
mitted to  the  mixture  is  adjusted  by  the  fuel-regulating  needle  G. 
while  the  amount  of  movement  of  the  auxiliary  air  valve  X  may  be 
controlled  by  the  air  valve  spring  tension  adjustment  shown  in  top 
sectional  view  at  B.  The  mixture  supplied  to  the  cylinders  is  gov- 
erned by  the  usual  form  of  disk  throttle  valve  T.  To  insure  easy 
starting  the  stop  K  may  be  turned  so  that  the  air  valve  is  held  closed, 
this  making  for  strong  suction  through  the  restricted  portion  of  the 
Venturi  tube  and  insuring  easy  starting  by  providing  a  rich  mixture. 

The  carburetor  shown  at  Fig.  151  is  that  used  on  Pierce  cars,  and 
is  illustrated  because  it  presents  a  number  of  novel  features.  While 
the  construction  in  the  main  follows  conventional  practice  inasmuch 
as  the  spray  nozzle  is  concentric  with  the  float,  it  employs  a  novel 
method  of  auxiliary  air  valve  control  and  a  form  of  throttle  which  is 


274 


The  Modern  Gasoline  Automobile 


275 


not  generally  used.  The  auxiliary  air  ports  are  regulated  by  reeds 
which  are  backed  by  supplementary  springs  to  prevent  excessive  mo- 
tion. The  reeds  open  progressively  as  the  suction  increases.  The 
throttle  chamber  contains  a  barrel-shaped  throttle  member  which  has 


Water  Outlet 


Water  Spa 
Water  Inlet 


Ball  Seat  Cage 
Float  Chamber  Cover 


Pipe  Connection 


Primary  Air  Inlet 


j.  152.— Grouvelle  and  Arquemberg  (French)  Carburetor  with  Venturi  Tube 
Mixing  Chamber  and  Air  Port  Control  by  Floating  Balls. 

>penings  cut  in  it  registering  with  the  gas  outlet  and  the  orifice  com- 
mnicating  with  the  mixing  chamber.  The  gasoline  supply  is  regu- 
ited  by  a  needle  valve  which  may  be  adjusted  to  regulate  the  size 

)f  the  opening  in  the  nozzle.    The  mixing  chamber  is  water- jacketed, 


276  The  Modern  Gasoline  Automobile 

and  as  the  stream  of  hot  water  from  the  engine  is  kept  circulating 
through  the  water  space  the  heat  tends  to  promote  more  positive 
vaporization  of  fuel  and  insure  thorough  mixture  of  gasoline  and 
air. 

The  Grouvelle  and  Arquemberg  carburetor  depicted  at  Fig.  152  is! 
a  foreign  type  that  has  been  applied  with  some  degree  of  success  in 
this  country.  The  float  chamber  is  carried  to  one  side  of  the  mixing 
chamber  and  the  usual  Venturi  tube  construction  is  followed.  No 
gasoline  regulation  is  possible  without  changing  the  spraying  nozzle,; 
and  as  the  auxiliary  air  supply  is  regulated  by  a  series  of  ball  valves 
this  adjustment  cannot  be  varied.  The  mixing  chamber  is  water- 
jacketed  and  the  amount  of  fuel  admitted  to  the  cylinders  is  regulated 
by  a  simple  disk  valve.  It  is  advanced  by  the  makers  of  this  apparatus 
that  once  fitted  to  an  engine  it  will  need  no  further  attention  and  H 
entirely  automatic  in  its  action.  The  combination  of  the  Venturi  tube 
and  the  floating  ball  auxiliary  air  control  are  said  to  provide  mixtures 
of  suitable  proportions  for  all  engine  speeds  without  using  adjustable 
members  which  are  liable  to  get  out  of  order  and  cause  trouble. 

Another  simple  form  of  carburetor  in  which  the  Venturi  tube 
effect  is  depended  upon  is  shown  at  Fig.  153.  In  this  device  the  car- 
buretor and  induction  pipe  are  a  unit.  The  float  chamber  is  carried, 
to  one  side  of  the  mixing  chamber  and  the  auxiliary  air  valve  and 
throttle  are  located  at  the  top  of  the  air  tube.  The  float  chamber  and 
spray  nozzle  construction  are  conventional,  but  the  combined  throttle 
and  air  valve  construction  is  unique.  The  air  valve  is  a  light  sheet 
metal  member  located  at  the  extreme  top  of  the  mixing  chamber  and 
held  to  its  seat  by  a  cone-shaped  helical  spring.  The  air  valve  is  guided 
by  the  throttle  stem.  The  throttle  consists  of  a  cylindrical  member 
connected  to  a- hub  by  four  ribs,  and  when  it  is  desired  to  shut  off  the 
gas  the  lower  portion  of  the  throttle  seats  against  the  top  of  the  air 
tube,  thus  effectively  shutting  off  the  branches  which  lead  to  the  cylin- 
der from  the  central  member. 

Owing  to  the  small  bore  of  the  mixing  chamber  a  rich  gas  is  in- 
spired'at  low  motor  speeds,  and  when  the  suction  effect  increases  the 
auxiliary  air  supply  enters  through  the  throttle  and  meets  the  incom- 
ing column  of  rich  gas  to  dilute  it  sufficiently  to  obtain  a  properly 
proportioned  mixture.  The  course  of  the  gas  is  direct,  rising  verti- 


The  Modern  Gasoline  Automobile 


277 


cally  from  the  top  of  the  spray  nozzle  to  the  throttle  where  it  branches 
to  the  two  inlet  pipes  forming  the  letter  Y. 


Float  Chamber 
\T 

Metal  Float 
Float  Value 


Primary  Air  Inlet 


Gasoline  Inlet-^        Spraying  Nozzle 


Fig.  153.—  Peerless  Carburetor,  which  is  Combined  with  Induction  Manifold. 
Has  Spray  Nozzle  and  Float  Chamber  at  Bottom  and  Air  Valve  at  Top. 


The  air  tube  is  water-  jacketed  its  full  length  to  insure  vaporization 
of  comparatively  low  grade  fuel.    The  main  air  entrance  is  through  a 


278  The  Modern  Gasoline  Automobile 

funnel-shaped  opening  provided  with  a  fine  mesh  screen,  past  a  hinged 
shutter  and  then  around  the  spray  nozzle.  The  function  of  the  shut- 
ter is  to  promote  easy  starting,  as  it  may  be  dropped  so  the  air  pipe 
is  almost  shut  off  when  it  is  desired  to  promote  high  gas  velocity  past 
the  top  of  the  spray  nozzle.  The  mixture  proportions  are  altered  by 
changing  the  tension  of  the  air  valve  spring  which  directly  affects  the 
degree  of  opening  and  the  amount  of  auxiliary  air  inspired. 

A  simple  form  of  automatic  carburetor  is  shown  at  Fig.  151. 
This  utilizes  a  concentric .  mixing  chamber  of  the  Venturi  tube  type. 
The  auxiliary  air  port  is  controlled  by  a  flat  seat  valve  and  the  gaso- 
line spray  is  regulated  by  an  overhead  needle  adjusting  tube.  The  air 
entrance  through  an  air  bend  at  the  bottom  of  the  carburetor  flows 
past  the  spray  nozzle  and  out  through  the  gas  outlet  which  is  con- 
trolled by  a  butterfly  throttle  valve.  A  feature  of  this  instrument  is 
the  detachable  strangling  tube  which  may  be  removed  in  case  the 
proper  adjustments  cannot  be  obtained  by  the  air  valve  and  gasoline 
needle  and  replaced  by  one  of  larger  or  smaller  bore  as  conditions 
demand. 

Multiple  Nozzle  Vaporizers. — To  secure  properly  proportioned  mix- 
tures some  carburetor  designers  have  evolved  forms  in  which  two  or 
more  nozzles  are  used  in  a  common  mixing  chamber.  The  usual  con- 
struction is  to  use  two,  one  having  a  small  opening  and  placed  in  a 
small  air  tube  and  used  only  for  low  speeds,  the  other  being  placed  in 
a  larger  air  tube  and  having  a  slightly  augmented  bore  so  that  it  is 
employed  on  intermediate  speeds.  At  high  speeds  both  jets  would  be 
used  in  series.  Some  multiple  jet  carburetors  could  be  considered  as  a 
series  of  these  instruments  each  one  being  designed  for  certain  con- 
ditions of  engine  action.  They  would  vary  from  small,  size  just  suf- 
ficient to  run  the -engine  at  low  speed  to  others  having  sufficient  capac- 
ity to  furnish  gas  for  the  highest  possible  engine  speed  when  used  in 
conjunction  with  the  smaller  members  which  have  been  brought  into 
service  progressively  as  the  engine  speed  has  been  augmented.  The 
multiple  nozzle  carburetor  differs  from  that  in  which  a  single  spray 
tube  is  used  only  in  the  construction  of  the  mixing  chamber,  as  a 
common  float  bowl  can  be  used  to  supply  all  spray  pipes.  It  is  com- 
mon practice  to  bring  the  jets  into  action  progressively  by  some  form 
of  mechanical  connection  with  the  throttle  or  by  automatic  valves. 


279 


280 


The  Modern  Gasoline  Automobile 


A  simple  form  of  multiple  jet  carburetor  h  shown  at  Fig.  155, 
this  being  an  adaptation  of  the  Stromberg  carburetor.  It  does  not 
differ  materially  from  the  single  jet  construction  except  that  there  is 


Needle  Valve  Li  ft  Lever, 
Gas  Outlet 


Priming  Lever 


Float  Level 
Adjustment  Loc 


Auxiliary  Ga.oline  Needle 


High  Speed 
Adjustment 


Auxiliary  Air 
Port 


Air  Value 
Spring 


Air  Value 
Lock 


Low  Speed 
Adjustment 
Auxiliary" 
Nozzle       ^Air  Valve  Stem 

Auxiliary  Jet 
Primary  Air  Inlet 
Primary  Jet 


Wire  Gauze 
Settling  Chambe 


Drain  Cock 


Fig.  156.— Details  of  Stromberg  Double- Jet  Carburetor,  which  Provides  Extra 
Fuel  Through  Auxiliary  Spray  Jet  when  Motor  Demands  It. 

an  auxiliary  nozzle  which  is  closed  by  a  spring-controlled  auxiliary 
gasoline  needle.  This  is  operated  by  a  needle  valve  lift  lever  which 
in  turn  is  affected  only  when  the  auxiliary  air  valve  is  drawn  down, 
a  certain  distance  by  the  motor  suction.  At  low  and  intermediate 
speeds  the  mixture  is  supplied  through  the  primary  jet  in  the  main 
mixing  chamber.  When  the  engine  speed  augments  to  such  an  extent 
that  the  auxiliary  air  valve  is  opened  to  a  certain  point  the  adjusting 


The  Modern  Gasoline  Automobile 


281 


nut  on  the  end  of  the  valve  stem  bears  against  the  long  arm  of  the 
lever  and  lifts  the  auxiliary  gasoline  needle  from  its  seat.  More  gaso- 
line is  then  sprayed  into  the  mixture  which  has  become  too  thin 
because  of  an  oversupply  of  air  through  the  auxiliary  valve  and  proper 
mixture  proportions  are  maintained. 


Fig.  156.— Carburetor  Incorporated  in  F.  I.  A.  T.  Cylinder  Casting  Is  a  Multiple- 
Jet  Type  Having  Two  Spray  Tubes. 

The  form  shown  at  Fig.  156  is  a  novel  one  in  several  respects.  It 
is  the  type  where  a  common  float  bowl  supplies  both  spray  nozzles. 
The  small  nozzle  A  is  used  at  low  speeds  and  is  brought  into  commu- 
nication with  the  throttle  chamber  C  by  a  small  port  in  the  throttle 


282  The  Modern  Gasoline  Automobile 

shell.  When  the  throttle  is  opened  still  further  to  secure  higher  speed 
of  the  motor  the  mixing  nozzle  B,  which  is  a  larger  one,  is  brought  into 
play  and  assists  the  nozzle  A,  which  would  be  inadequate  if  used  alone. 
The  auxiliary  air  enters  through  the  openings  E  which  are  also  con- 
trolled by  ports  in  the  throttle  shell.  One  of  the  most  distinctive 
features  of  this  carburetor  is  the  manner  in  which  it  is  incorporated 
with  the  cylinder  unit  casting,  it  being  installed  at  a  point  between 
the  pairs  of  the  cylinders.  The  induction  manifold  is  formed  integral 
with  the  cylinder  casting  and  no  outside  manifold  is  used  or  needed. 
The  throttle  assembly  is  formed  as  a  unit  and  inserted  into  a  suitably 
machined  opening  while  the  float  chamber  and  spray  nozzle  assembly 
is  inserted  at  the  lower  portion  as  another  unit. 

A  simple  form  of  two-jet  carburetor  having  an  automatic  control 
of  the  mixing  chamber  is  shown  in  section  at  Fig.  157.  In  this  a 
clack  valve  is  used  to  close  off  the  secondary  mixing  chamber  at  low 
speeds.  All  the  air  is  drawn  through  a  common  opening  and  deliv- 
ered to  an  annular  air  chamber  which  surrounds  the  mixing  chamber. 
This  permits  one  air  inlet  to  serve  both  primary  ;;nd  secondary  mixing 
chambers.  At  low  throttle  openings  only  the  primary  nozzle  is  util- 
ized and  the  amount  of  gasoline  supplied  can  be  adjusted  to  a  degree 
which  will  insure  a  mixture  of  such  proportions  as  will  produce  steady 
running  with  minimum  gasoline  consumption. 

When  the  throttle  is  opened  to  increase  engine  speed  the  degree 
of  suction  is  increased  and  at  a  time  that  the  primary  nozzle  is  not 
adequate  to  supply  a  full  charge  of  gas  the  clack  valve  opens  auto- 
matically and  the  secondary  nozzle  is  brought  into  play.  The  valve 
is  joined  to  a  piston  which  works  in  a  dashpot  by  means  of  a  crank 
and  connecting  rod  in  order  that  its  movement  will  be  gradual.  The 
coil  spring  back  of  tLo  dashpot  piston  tends  to  keep  the  valve  closed 
until  the  higher  degree  of  vacuum  or  suction  causes  the  valve  to  open 
against  the  spring  resistance.  If  the  throttle  were  suddenly  closed 
the  tendency  of  the  valve  might  be  to  close  very  rapidly  and  to  pre- 
vent too  rapid  movement  of  this  member  the  piston  is  moved  against 
an  air  cushion  at  the  bottom  of  the  dashpot  cylinder.  As  this  member 
must  oscillate  to  a  certain  extent  when  the  shutter  works  back  and 
forth  it  is  jonrnaled  at  its  lower  end  to  permit  a  certain  degree  of 
movement.  As  will  be  evident  both  spray  nozzles  furnish  mixture  at 


283 


284  The  Modern  Gasoline  Automobile 

high  engine  speeds.  The  view  shown  at  A  depicts  clearly  the  con- 
struction of  the  clack  valve  and  how  its  motion  is  controlled  by  the 
crank,  connecting  rod  and*  piston  in  the  dashpot  cylinder.  The  view 
at  B  depicts  clearly  the  arrangement  of  the  float  and  mixing  cham- 
bers, and  the  method  of  supplying  both  primary  and  secondary  nozzles 
with  air  through  one  main  air  inlet  and  with  gasoline  from  a  common 
source. 

In  the  Zenith  carburetor,  which  is  shown  at  Fig.  158,  a  compound 
nozzle  is  used,  this  being  composed  of  two  jets  designated  as  G  and  H. 
The  center  nozzle  G  is  the  main  member  and  concentric  with  it  is  a 
ti^be  which  forms  the  compensating  jet  H.  The  inner  nozzle  com- 
municates with  the  float  chamber  through  passages  E  and  C,  while 
the  annular  space  between  the  main  jet  and  the  cap  of  the  compen- 
sating member  is  supplied  with  gasoline  by  the  passage  F.  At  one 
side  of  the  mixing  chamber,  and  between  that  member  and  the  float 
compartment,  is  a  cylinder  in  which  the  secondary  well  P  and  the 
priming  tube  K  are  suspended.  The  upper  end  of  the  priming  tube 
is  in  communication  with  tb°  passage  IT  in  the  mixing  chamber  walls. 
The  passage  U  is  controlled  by  the  throttle  T.  When  the  throttle  is 
closed  the  suction  through  the  priming  tube  K  is  so  great  that  it 
drains  the  gasoline  from  the  secondary  well  and  furnishes  a  very  rich 
mixture  through  the  opening  U  in  the  wall  of  the  air  tube  D.  The 
gasoline  enters  the  secondary  well  P  through  the  small  hole  Q  at  the 
bottom.  With  this  vaporizer  the  quantity  of  air  increases  almost 
directly  as  the  engine  speed  but  the  gasoline  supply  does  not. 

Since  the  air  supply  increases  with  a  constant  ratio  the  amount  of 
gasoline  must  be  regulated  to  such  proportions  that  a  correct  mixture 
will  be  obtained  at  all  speeds.  This  is  the  function  performed  by  the 
double  nozzle  because  at  low  speed  the  outer  or  compensating  nozzle 
has  a  large  quantity  of  fuel,  but  this  decreases  as  the  engine  speed 
augments  until  at  high  speed  the  compensating  nozzle  does  not  add 
much  fuel  to  the  mixture.  In  this  form  the  multiple  nozzle  construc- 
tion is  employed  to  do  away  with  the  automatic  air  valve,  all  air 
being  di*awn  through  the  primary  air  opening  at  the  bottom  of  the 
mixing  tube  D.  A  strangling  tube  A  is  dropped  into  the  air  tube  in 
order  to  constrict  its  area  at  the  spray  nozzle  and  secure  a  Venturi 
tube  effect. 


The  Modern  Gasoline  Automobile 


285 


The  object  of  any  multiple  nozzle  carburetor  is  to  secure  greater 
flexibility  and  endeavor  to  supply  mixtures  of  proper  proportions  at 
all  speeds  of  the  engine.  It  should  be  stated,  however,  that  while 
devices  of  this  nature  lend  themselves  readily  to  practical  application 


Fig.  158.— The  Zenith  Carburetor,  which  Embodies  Novel  Application  of  Double- 
Jet  Principle,  One  Spray  Nozzle  Being  Concentric  with  the  Other. 

it  is  more  difficult  to  adjust  them  than  the  simpler  forms,  having  but 
one  nozzle.  When  a  number  of  jets  are  used  the  liability  of  clogging 
up  the  carburetor  is  increased,  and  if  one  or  more  of  the  nozzles  is 
choked  by  a  particle  of  dirt  or  water  the  resulting  mixture  trouble  is 


286  The  Modern  Gasoline  Automobile 

difficult  to  detect.  One  of  the  nozzles  may  supply  enough  gasoline  to 
permit  the  engine  to  run  well  at  certain  speeds  and  yet  not  be  ade- 
quate to  supply  the  proper  amount  of  gas  under  other  conditions. 

In  adjusting  a  multiple  jet  carburetor  in  which  the  jets  are  pro- 
vided with  gasoline  regulating  needles,  it  is  customary  to  consider 
each  nozzle  as  a  distinct  carburetor  and  to  regulate  it  to  secure  the 
best  motor  action  at  that  throttle  position  which  corresponds  to  the 
conditions  under  which  the  jet  is  brought  into  service.  For  instance, 
that  supplied  the  primary  mixing  chamber  should  be  regulated  Avith 
the  throttle  partly  closed,  while  the  auxiliary  jet  should  be  adjusted 
with  the  throttle  fully  opened. 

Utility  of  Gasoline  Strainers. — Many  carburetors  include  a  filter- 
ing screen  at  the  point  where  the  liquid  enters  the  float  chamber  in 
order  to  keep  dirt  or  any  other  foreign  matter  which  may  be  present 
in  the  fuel  from  entering  the  float  chamber.  This  is  not  general  prac- 
tice, however,  and  the  majority  of  vaporizers  do  not  include  a  filter  in 
their  construction.  It  is  very  desirable  that  the  dirt  should  be  kept 
out  of  the  carburetor  because  it  may  get  under  the  float  control  fuel 
valve  and  cause  flooding  by  keeping  it  raised  from  its  seat.  If  it  finds 
its  way  into  the  spray  nozzle  it  may  block  the  opening  so  that  no 
gasoline  will  issue  or  may  so  constrict  the  passage  that  only  very  small 
quantities  of  fuel  will  be  supplied  the  mixture.  Where  the  carburetor 
itself  is  not  provided  with  a  filtering  screen  a  simple  filter  is  usually 
installed  in  the  pipe  line  between  the  gasoline  tank  and  the  float 
chamber. 

Some  simple  forms  of  filters  and  separators  are  shown  at  Fig.  159. 
That  at  A  consists  of  a  simple  brass  casting  having  a  readily  detach- 
able gauze  screen  and  a  settling  chamber  of  sufficient  capacity  to  allow 
the  foreign  matter  to  settle  to  the  bottom  from  which  it  is  drained  out 
by  a  pet  cock.  Any  water  or  dirt  in  the  gasoline  will  settle  to  the 
bottom  of  the  chamber,  and  as  all  fuel  delivered  to  the  carburetor 
must  pass  through  the  wire  gauze  screen  it  is  not  likely  to  contain 
impurities  when  it  reaches  the  float  chamber.  The  heavier  particles, 
such  a&%scale  from  the  tank  or  dirt  and  even  water,  all  of  which  have 
greater  weight  than  the  gasoline,  will  sink  to  the  bottom  of  the  cham- 
ber, whereas  light  particles,  such  as  lint,  will  be  prevented  from  flow- 
ing into  the  carburetor  by  the  filtering  screen. 


The  Modern  Gasoline  Automobile 


287 


The  filtering  device  shown  at  B  is  a  larger  appliance  than  that 
shown  at  A,  and  should  be  more  efficient  as  a  separator  because  the 
gasoline  is  forced  to  pass  through  three  filtering  screens  before  it 
reaches  the  carburetor.  The  gasoline  enters  the  device  shown  at  C 


Supporting  Boss 


Gasoline 
from  Tank 


To  Carburetor 


__  v  To  Carburetor 


Wire  Gauze 


Wire  Gauze 

Settling  Chamber 
Settling  Chamber 


B 


Gasoline  Tank 


To  Carburetor 


Wire  Gauze  \* 

To  Carburetor} 


Settling  Chamber 

Settling  Chamber 


Fig.  159. — Types  of  Strainers  Interposed  Between  Vaporizer  and  Gasoline  Tank 
to  Prevent  Water  or  Dirt  Passing  Into  Carbureting  Device. 

through  a  bent  pipe  which  leads  directly  to  the  settling  chamber  and 
from  thence  through  a  wire  gauze  screen  to  the  upper  compartment 
which  leads  to  'the  carburetor.  The  device  shown  at  D  is  used  on 
Chalmers  motor  cars  and  is  a  combination  strainer,  drain,  and  sedi- 
ment cup.  The  filtering  screen  is  held  in  place  by  a  spring  and  both 


288  The  Modern  Gasoline  Automobile 

are  removed  by  taking  out  a  plug  at  the  bottom  of  the  device.  The 
shut-off  valve  at  the  top  of  the  device  is  interposed  between  the  sedi- 
ment cup  and  the  carburetor.  This  separating  device  is  incorporated 
with  the  gasoline  tank  and  forms  an  integral  part  of  the  gasoline  sup- 
ply system.  The  other  types  shown  are  designed  to  be  interposed 
between  the  gasoline  tank  and  the  carburetor  at  any  point  in  the  pipe 
line  where  they  may  be  conveniently  placed. 

How   Kerosene   May   be   Utilized. — The   carburetion   of   kerosene 
seems  to  be  partially  solved  at  the  present  time,  and  there  are  several 
forms  of  carbureting  devices  which  permit  one  to  utilize  this  fuel. 
It  is  important  that  the  vaporizer  employed  be  one  that  can  be  readily   \ 
adapted  to  present  day  forms  of  motors.     It  is  a  fact  that  with  lower 
grade   fuels,   as  kerosene   or  benzol,  a  motor   of  lower   compression 
than  one  can  use  successfully  with  gasoline  and  some  means  for  heat-   j 
ing  the  entering  mixture  are  needed.     When  kerosene  is  used  as  fuel  | 
the  conditions  are  similar  to  those  which  obtain  with  gasoline  except  | 
the  temperature  at  which  vaporization  commences.    The  heavier  liquid 
requires  more  heat  to  cause  it  to  vaporize,  it  being  necessary  to  pre- 
heat kerosene  to  about  two  hundred  degrees  Fahrenheit  before  it  will 
evaporate  and  form  a  mixture  with  air.     !•;  is  necessary  to  provide  a  | 
heated  passage  to  further  vaporize  the  mixture  as  it  leaves  the  spray 
nozzle  and  as  direct  an  entrance  to  the  motor  should  be  provided  as 
possible.     It  is  necessary  to  maintain  a  high  velocity  of  the  kerosene 
vapor  in  order  to  prevent  condensation. 

The  carburetor  depicted  at  Fig.  160  is  the  Holley  form  adapted  to 
use  kerosene.  It  consists  of  a  conventional  form  concentric  jet,  float- 
feed  vaporizer,  to  which  the  kerosene  is  fed  at  the  lower  end  and  a  mix- 
ing chamber  having  an  auxiliary  air  valve  is  carried  at  the  upper  end  \ 
of  the  device.  In  connection  with  this  appliance  a  simple  form  of 
gasoline  vaporizing  valve  is  mounted  at  the  upper  end  near  the  gas 
outlet,  and  is  used  to  supply  mixture  enough  to  promote  easy  starting 
of  the  motor.  The  exhaust  gases  from  the  motor  are  passed  through 
a  jacket  which  surrounds  the  mixture  tube  leading  from  the  kerosene 
vaporizer  and  which  goes  through  the  float  bowl  to  heat  the  fuel 
therein. 

The  liquid  in  the  fuel  container  is  heated  to  about  two  hundred 
degrees  before  it  is  sprayed  in  the  motor,  and  it  is  contended  that  if 


The  Modern  Gasoline  Automobile 


289 


kerosene  is  kept  near  its  boiling  point  it  will  leave  the  spray  nozzle 
just  as  readily  as  gasoline  will  at  ordinary  temperature.  It  would  be 
extremely  difficult  to  start  an  engine  on  kerosene  unless  the  vaporiz- 


Gasoline 
Vaporizing  Value 


Adjusting  Needle 
Clamp 


Exhaust  Inle 


Spraying  Nozzle 

Float  Valve  Cap 

Float  Valve 
loot  Chamber 

Kerosene  Inlet 


Primary  Air  Injet 


Fig.  160. — Holley  Combined  Gasoline  and  Kerosene  Carburetor.  May  Be  Used 
with  Either  Fuel,  Though  Specially  Adapted  for  the  Less  Volatile  Liquid 
Distillates  of  Petroleum,  Because  of  Preheating  Arrangement. 


290 


The  Modern  Gasoline  Automobile 


ing  device  was  raised  in  temperature  to  a  point  that  would  permit  of 
/  ready  vaporization  of  fuel.  In  the  device  shown  at  Fig.  160  if  the 
motor  is  to  be  started  cold  the  mixture  supplied  by  the  gasoline  vapor- 
izing valve  is  directed  into  the  cylinder  by  a  three-way  valve  which 
closes  off  the  kerosene  compartment  and  provides  a  by-pass  for  the 
gasoline  mixture  through  the  gas  outlet.  After  the  engine  has  run 
for  a  time,  usually  two  or  three  minutes,  the  kerosene  vaporizer  has 
been  raised  in  temperature  to  the  proper  point  and  a  shift  from  one 
fuel  to  another  is  easily  made  by  throwing  the  three-way  valve  over 
so  that  the  gasoline  vaporizer  is  shut  off  from  the  gas  outlet  and  direct 
communication  is  provided  by  the  large  opening  in  the  throttle  valve 
between  the  motor  cylinder  and  the  mixing  chamber  of  the  kerosene 
carburetor. 

When  kerosene  vapor  is  used  with  the  usual  type  of  induction 
manifold  it  is  liable  to  condense  if  conditions  are  unfavorable  to  rapid 


.  Exhaust 


Exhaust 


Fig.  161. — Combined  Intake  and  Exhaust  Manifold  Suggested  as  Suitable  f( 
Use  with  Kerosene  and  Air  Mixture.     The  Hot  Exhaust  Gases  Heat 
Inlet  Pipe  Walls  and  Produce  More  Complete  Vaporization. 

volatilization.  This  "  loading  up  "  as  it  is  called  is  due  to  the  lo\v 
velocity  and  temperature  of  the  mixture  which  passes  through  com- 
paratively large  passages,  and  while  it  can  be  reduced  to  a  certaii 
extent  by  making  the  area  of  the  manifold  cross  section  smaller,  thu 
is  not  desirable  because  at  high  speeds  it  would  not  be  possible 
supply  san  adequate  amount  of  mixture  to  the  cylinders  unless  the  ful 
cross  section  of  the  intake  pipe  is  used.  To  minimize  condensatioi 
the  combination  manifold  shown  at  Fig.  161  has  been  recommend< 
This  consists  of  forming  the  intake  and  exhaust  manifold  in  01 


The  Modern  Gasoline  Automobile  291 

casting,  the  thought  being  to  heat  the  inlet  manifold  by  the  hot  inert 
products  of  combustion  to  such  a  point  that  the  kerosene  vapor  would 
be  turned  into  a  gas  and  all  liquid  particles  vaporized.  It  is  recom- 
mended that  a  manifold  of  this  type  be  used  in  connection  with  the 
carburetor  shown  at  Fig.  160. 

It  is  stated  that  the  heated  vapor  from  the  kerosene  vaporizer  with 
its  quota  of  air  comprises  about  one  fourth  of  the  total  volume  of  the 
charge,  the  balance  of  the  air  being  supplied  by  the  auxiliary  valve 
at  the  top  of  the  kerosene  vaporizer.  When  the  proper  degree  of  com- 
pression obtains  in  the  motor  and  the  kerosene  is  properly  heated 
before  attempt  is  made  to  vaporize  it  the  action  of  the  carburetor  de- 
scribed is  claimed  to  be  very  similar  to  that  of  a  gasoline  vaporizer. 
It  is  claimed  that  it  is  possible  to  convert  the  usual  gasoline  motor  by 
adding  a  spacer  of  proper  thickness  under  the  cylinder  to  reduce  the 
compression  to  the  point  where  kerosene  can  be  used  successfully. 
The  degree  of  compression  recommended  as  most  suitable  for  use  with 
kerosene  vapor  furnished  by  a  carbureting  device  is  between  fifty  and 
sixty  pounds  per  square  inch. 

Another  important  consideration  is  that  the  initial  heating  of  the 
lotor  parts  by  use  of  gasoline  gas  be  complete  before  one  attempts  to 
ise  kerosene.     If  the  heavier  liquid  is  supplied  to  the  engine  before 
the  carburetor  has  been  raised  to  the  proper  degree  of  temperature, 
poor  combustion  of  kerosene  results  and  carbon  deposits,  or  gummy 
residue  is  deposited  in  the  interior  of  the  combustion  chamber. 

Supplying  Kerosene  by  Direct  Injection. — The  most  logical  method 
of  utilizing  fuels  which  have  a  low  vaporizing  point  and  which  must 
be  raised  in  temperature  before  they  will  give  off  vapor  is  to  supply 
to  the  motor  cylinder  by  direct  injection.  Several  types  of  stationary 
>wer  plants  and  some  used  in  marine  applications  have  been  designed 

use  the  cheaper  fuels  which  cost  less  than  gasoline,  such  as  kerosene, 
benzol,  or  crude  oil.     The  view  at  Fig.  162  is  a  section  through  a 

>troit  two-port  two-cycle  engine  which  has  been  adapted  to  use  kero- 

ic  by  direct  injection.     The  engine  is  of  the  conventional  pattern, 
iving  an  automatic  inlet  valve  at  the  side  of  the  crank  case  to  admit 
tir  on  the  upward  stroke  of  the  piston.    If  this  engine  was  used  with 

>oline  the  carburetor  or  mixing  valve  would  be  attached  to  this  check 
falve  cage  and  the  engine  would  operate  on  the  two-port  principle. 


292 


The  Modern  Gasoline  Automobile 


In  the  design  under  discussion  the  fuel  supply  device  consists  of  a 
float  feed  arrangement  attached  to  a  spray  nozzle  placed  in  the  trans- 
fer port  in  such  a  way  that  it  discharges  the  fuel  against  the  deflector 


Water  Space 


Nater  Space 


Float 


Fuel 

Connection 
A 


Air  Passage  from 
Crankcase  to  Cylinder   t      Cranhcase  Q 


Fig.  162. — Showing  Two-Cycle  Motor  with  Device  for  Direct  Injection  of  Heav- 
ier Petroleum  Distillates  into  Cylinder. 

plate  on  the  piston  top.  The  float  keeps  the  kerosene  level  in  the 
float  chamber  to  a  height  equal  to  the  point  of  the  spray  jet.  The 
amount  of  kerosene  supplied  can  be  regulated  by  the  usual  needle 
valve  which  controls  the  nozzle  opening. 


The  Modern  Gasoline  Automobile  293 

Assume  for  the  purpose  of  making  the  explanation  clearer  that  the 
binder  is  full  of  fresh  gas  and  that  the  piston  is  traveling  upward. 
[t  will  close  the  transfer  passage  and  the  exhaust  port  and  will  com- 
press the  charge  above  it.  As  the  piston  continues  to  move  upward 
a  vacuum  is  created  in  the  crank  case  0  which  draws  in  a  current  of 
air  through  the  spring-controlled  automatic  valve  P,  and  fuel  into  the 
fuel-feeding  chamber.  At  the  top  of  the  compression  stroke  the  gas 
is  ignited  by  an  electric  spark  and  the  resulting  explosion  causes  a 
downward  movement  of  the  piston.  As  this  member  moves  toward 
the  end  of  its  stroke  the  air  in  the  crank  case  and  the  fuel-supply 
chamber  is  under  compression.  As  the  exhaust  port  is  uncovered  by 
the  piston  as  it  continues  to  go  down  the  inert  products  of  combus- 
tion, which  have  a  pressure  of  forty  to  fifty  pounds  per  square  inch, 
stream  out  of  the  open  port  until  but  a  very  small  portion  of  burned 
gas  which  is  at  atmospheric  pressure  remains  at  the  cylinder. 

As  the  piston  continues  to  move  down  it  uncovers  the  spraying 
nozzle  I.  The  compressed  air  in  the  crank  case  rushes  into  the  cylin- 
der F  and  strikes  the  deflector  H  which  directs  it  to  the  top  of  the 
cylinder  and  drives  before  it  the  remainder  of  the  burned  gases  out  of 
the  open  exhaust  port.  Simultaneously  with  this  function  the  pres- 
sure in  the  fuel  chamber  B  relieves  itself  by  spraying  a  stream  of  fuel 
through  the  nozzle  I,  As  this  stream  of  liquid  strikes  the  hot  de- 
flector plate  it  is  immediately  vaporized,  and  as  it  is  in  the  center  of 
the  incoming  air  stream  it  mixes  with  it  to  form  an  inflammable 
mixture. 

A  disadvantage  of  this  method  of  fuel  injection  is  that  it  does  not 
provide  for  the  flexibility  of  engine  action  which  is  so  essential  in 
automobile  service.  This  disadvantage  does  not  militate  against  it 
to  any  great  extent  in  stationary  or  marine  application  where  the 
motor  speed  does  not  need  to  be  varied  within  a  wide  range  and 
where  constant  speeds  are  more  often  used.  This  method  of  auto- 
matic fuel  injection  is  not  practical  when  a  four-cycle  engine  is  used, 
and  if  fuel  is  to  be  suppled  in  this  manner  a  small  plunger  pump 
driven  by  the  engine  is  usually  employed  to  force  it  into  the  combus- 
tion chamber  under  considerable  pressure. 

Intake  Manifold  Design  and  Construction. — On  four-  and  six-cylin- 
der engines  and  in  fact  on  all  multiple-cylinder  forms,  it  is  important 


294  The  Modern  Gasoline  Automobile 

that  the  piping  leading  from  the  carburetor  to  the  cylinders  be  made 
in. such  a  way  that  the  various  c}dinders  will  receive  their  full  quota 
of  gas  and  that  each  cylinder  will  receive  its  charge  at  about  the  same 
point  in  the  cycle  of  operations.  In  order  to  make  the  passages  direct 
the  bends  should  be  as  few  as  possible,  and  when  curves  are  necessary 
they  should  be  of  large  radius  because  an  abrupt  corner  will  not  only 
impede  gas  flow  but  will  tend  to  promote  condensation  of  the  fuel. 
Every  precaution  should  be  taken  with  four-  and  six-cylinder  engines 
to  insure  equitable  gas  distribution  to  the  valve  chambers  if  regular 
action  of  the  power  plant  is  desired.  If  the  gas  pipe  has  many  turns 
and  angles  it  will  be  difficult  to  charge  all  cylinders  properly. 

The  problem  of  intake  piping  is  simplified  to  some  extent  on 
block  motors  where  the  intake  passage  is  cored  in  the  cylinder  casting 
and  where  but  one  short  pipe  is  needed  to  join  this  passage  to  the 
carburetor.  If  the  cylinders  are  cast  in  pairs  a  simple  pipe  of  T 
or  Y  form  can  be  used  with  success.  When  the  engine  is  of  a  type 
using  individual  cylinder  castings,  especially  in  the  six-cylinder  power 
plants,  the  proper  application  and  installation  of  suitable  piping  is  a 
difficult  problem. 

Intake  piping  is  constructed  in  two  ways,  the  most  common 
method  being  to  cast  the  manifold  of  brass  or  aluminum.  The  other 
method,  which  is  more  costly,  is  to  use  a  built-up  construction  of  cop- 
per or  brass  tubing  with  cast  metal  elbows  and  Y  pieces.  One  of  the 
disadvantages  advanced  .against  the  cast  manifold  is  that  blowholes 
may  exist  which  produce  imperfect  castings  and  which  will  cause  mix- 
ture troubles  because  the  entering  gas  from  the  carburetor,  which  may 
be  of  proper  proportions,  is  diluted  by  the  excess  air  which  leaks  in 
through  the  porous  casting.  Another  factor  of  some  moment  is 
that  the  roughness  of  the  walls  have  a  certain  amount  of  friction 
which  tends  to  reduce  the  velocity  of  the  gases,  and  when  project- 
ing pieces  are  present,  such  as  core  wire  or  other  points  of  metal, 
these  tend  to  collect  the  drops  of  liquid  fuel  and  thus  promote  con- 
densation. 

The  advantage  of  the  built-up  construction  is  that  the  walls  of  the 
tubing  are  very  smooth,  and  as  the  castings  are  small  it  is  not  difficult 
to  clean  them  out  thoroughly  before  they  are  incorporated  in  I  lie 
manifold.  The  tubing  and  castings  are  joined  together  by  hard  sol- 


The  Modern  Gasoline  Automobile 


295 


clering  or  brazing,  and  extreme  care  is  needed  to  insure  tight  joints 
at  all  points. 

Some  typical  manifolds  used  on  four-cylinder  engines  of  various 
types  are  depicted  at  Fig.  163.  That  at  A  is  composed  of  four  pipes 
leading  from  a  central  member,  each  one  communicating  with  an 


Fig.  163. — Typical  Induction  Pipes  Used  on  Four-Cylinder  Motors. 

idividual  cylinder.  The  pipes'  are  so.  nearly  the  same  length  that 
distribution  is  fairly  uniform.  The  manifolds  shown  at  B  and  C 
substantially  the  same,  except  that  one  is  a  more  pronounced  Y 
lan  the  other.  Both  are  cast  forms,  that  at  B  being  of  round  section, 
rhile  that  at  C  is  a  square  section  casting.  The  manifold  depicted  at 
is  another  type  which  has  been  evolved  for  use  with  a  four-cylinder 
lotor  having  individual  cylinder  castings. 

At  E  a  cast  manifold  which  is  combined  with  a  water-jacket  cover 

ite  used  on  the  Chalmers  block  motor  is  illustrated,  it  being  plain 

iat  the  heating  effect  of  the  jacket-water  tends  to  raise  the  tempera- 


296 


The  Modern  Gasoline  Automobile 


ture  of  the  entire  manifold  and  promote  more  rapid  vaporization  if 
low-grade  fuels  are  used.  The  manifold  at  F  is  a  type  applied  to  a 
four-cylinder  motor  having  cylinders  cast  in  pairs,  and  this  cast  form 
has-been  made  with  graceful  curves  rather  than  straight  lines.  The 
induction  pipe  depicted  at  G  is  also  utilized  to  supply  a  four-cylinder 
motor  having  twin  cylinder  castings  and  is  made  in  the  form  of  a 
letter  T.  At  H  a  ramshorn  type  is  outlined,  the  curves  being  reversed 
to  the  usual  construction.  The  form  at  I  is  still  another  variation  of 
the  simple  two-branch  or  T  form  of  induction  pipe. 


Fig.  164. — Conventional  Inlet  Manifolds  Adapted  for  Six-Cylinder  Motors. 

When  six-cylinder  motors  are  used  the  problem  is  one  that  is  not 
so  easily  solved,  and  designers  show  considerable  ingenuity  in  devising 
manifolds  to  secure  even  charge  distribution.  A  number  of  conven- 
tional forms  that  have  received  successful  application  are  depicted  at 
Fig.  164  All  types  shown  except  that  outlined  at  D  are  used  with  six- 
cylinder  engines  having  three  pairs  of  cylinders,  while  that  at  D  is 
employed  when  the  motor  is  composed  of  two  three-cylinder  block 
castings.  All  the  manifolds  illustrated  are  built-up  forms  composed 


The  Modern  Gasoline  Automobile 


297 


of  tubing  and  cast  fittings  with  the  exception  of  that  outlined  at  C, 
which  is  a  cast  aluminum  member. 

Another  group  of  six-cylinder  manifolds  is  given  at  Fig.  165.    The 
forms  at  A,  B,  C,  and  E  are  designed  for  use  with  six-cylinder  motors 


72345  6 


1  23456 


Fig.  165. — Some  Unconventional  Forms  of  Gas  Supply  Pipes  Used  On  Six-Cylin- 
der Power  Plants. 

having  individual  cylinder  castings.  The  form  at  A,  while  of  peculiar 
shape,  provides  gas  passages  of  about  the  same  length  leading  to  all 
cylinders.  This  is  not  true  of  those  shown  at  B,  C,  and  E,  which  are 
faulty  in  design,  inasmuch  as  the  gas  will  reach  cylinders  three  and 
four  much  quicker  than  it  will  get  to  two  and  five,  and  to  these  two 
cylinders  quicker  than  it  will  reach  those  on  the  extreme  ends  of  the 
manifold,  or  one  and  six.  It  is  claimed  that  the  loop  shown  at  B  has 
given  very  satisfactory  results,  and  that  the  peculiar  construction 
compensates  to  a  certain  degree  for  the  varying  lengths  of  piping 
leading  from  the  carburetor  to  the  various  valve  chambers.  The 
manifold  at  D  is  a  built-up  form  utilized  when  cylinders  are  cast  in 
pairs,  and  is  much  superior  to  that  outlined  at  F,  which  is  a  cast 
aluminum  member  designed  for  the  same  type  of  motor. 


298  The  Modern  Gasoline  Automobile 

Compensating  for  Varying  Atmospheric  Conditions. — The  low- 
grade  gasoline  used  at  the  present  time  makes  it  necessary  to  use 
vaporizers  that  are  more  susceptible  to  atmospheric  variations  than 
when  higher  grade  and  more  volatile  liquids  are  vaporized.  Sudden 
temperature  changes,  sometimes  being  as  much  as  forty  degrees  rise 
or  fall  in  twelve  hours,  affect  the  mixture  proportions  to  some  extent, 
and  not  only  changes  in  temperature  but  variations  in  altitude  also 
have  a  bearing  on  mixture  proportions  by  affecting  both  gasoline 
and  air.  As  the  temperature  falls  the  specific  gravity  of  the  gasoline 
increases  and  it  becomes  heavier,  this  producing  difficulty  in  vaporiz- 
ing. The  tendency  of  very  cold  air  is  to  condense  gasoline  instead 
of  vaporizing  it  and  therefore  it  is  necessary  to  supply  heated  air  to 
some  carburetors  to  obtain  proper  mixtures  during  cold  weather.  In 
order  that  the  gas  mixtures  will  ignite  properly  the  fuel  must  be 
vaporized  and  thoroughly  mixed  with  the  entering  air  either  by  heat 
or  high  velocity  of  the  gases. 

As  it  would  be  somewhat  inconvenient  to  constantly  regulate  the 
average  carburetor  from  day  to  day  by  the  regular  adjustments  incor- 
porated in  the  device,  forms  o.'  dash-controlled  regulators  have  been 
devised.  One  of  these  is  shown  at  Fig.  166  as  applied  to  the  Holley 
carburetor.  It  consists  of  a  special  form  of  valve  interposed  between 
the  hot  air  connection  around  the  exhaust  manifold  and  the  primary 
air  entrance  at  the  side  of  the  carburetor.  It  is  worked  by  a  simple 
key  and  leverage  connection.  An  indicator  plate  on  the  dash  shows 
the  different  positions  of  the  regulator.  When  the  shutter  is  in  the 
position  shewn  at  A  only  cold  air  is  supplied  the  carburetor,  this  be- 
ing the  proper  position  for  summer  running.  When  in  the  position 
shown  at  B  the  cold  air  slot  is  closed  and  only  warm  air  which  is  taken 
from  the  jacket  surrounding  the  exhaust  pipe  is  supplied  the  car- 
buretor. This  'would  be  the  proper  position  for  cold  or  damp 
weather.  If  the  shutter  is  placed  as  shown  at  C  the  air  supplied  the 
carburetor  will  be  composed  of  both  warm  and  cold  currents  in  any 
desired  proportion.  When  it  is  desired  to  exert  a  strong  suction  on 
the  gasoline  in  the  carburetor,  as  is  often  necessary  in  starting,  the 
shutter  may  be  turned  as  depicted  at  D  in  which  case  both  air  open- 
ings are  shut  off  with  the  exception  of  but  a  very  small  slot.  The 
equipment  illustrated  has  been  designed  especially  for  use  with  the 


299 


300  The  Modern  Gasoline  Automobile 

Holley  carburetor  and  is  supplied  by  the  manufacturers  of  that  device. 
Air  shutter  regulation  has  been  used  on  many  cars,  however,  and  has 
proved  to  be  a  very  satisfactory  way  of  compensating  for  extremes  of 
temperature  or  altitude  and  variations  in  fuel  quality. 

Disposition  of  Exhaust  Gases. — While  the  problem  of  getting  the 
fresh  gases  into  the  cylinders  is  an  important  one  the  means  of  dis- 
posing of  them  after  they  have  been  burned  is  also  important.  The 
form  of  the  exhaust  manifold,  which  is  usually  a  large  malleable  iron 
casting,  is  not  so  important  as  that  of  the  induction  pipe  and  the 
chief  precaution  to  be  observed  is  to  make  the  passages  in  this  mem- 
ber as  large  as  possible  and  to  proportion  it  in  such  a  way  that 
all  parts  of  the  casting  will  expand  with  the  same  ratio.  An  impor- 
tant condition  to  be  observed,  however,  is  the  method  of  discharging 
the  gases  to  the  air  and  for  this  purpose  various  forms  of  mufflers, 
or  silencers,  are  used  so  that  the  gases  will  be  discharged  in  an  un- 
objectionable manner. 

It  has  been  demonstrated  that  the  average  motor  vehicle  engine 
cannot  utilize  the  full  expansive  force  of  the  burned  charge  because 
the  exhaust  valve  is  opened  a  certain  number  of  degrees  before  the 
bottom  center  or  before  the  piston  reaches  the  end  of  its  power  stroke. 
This  is  done  to  give  a  lead  or  start  to  the  gases  and  obtain  higher 
engine  speeds  than  would  otherwise  be  possible.  As  a  result  of  the 
early  opening  of  the  exhaust  valve  the  gases  will  issue  through  the 
valve  port  at  sufficient  pressure  to  produce  a  report  like  a  gun  shot 
which  would  be  apt  to  disturb  persons  and  animals  of  nervous  tem- 
perament and  at  the  same  time  not  be  exactly  music  to  the  normal  ear. 

It  is  not  difficult  to  muffle  the  gases  so  there  will  be  but  little  noise 
to  the  exhaust,  but  it  is  quite  a  problem  to  do  it  without  producing 
back  pressure  in  the  muffling  device  that  will  cause  serious  loss  of 
power.  A  muffler  should  offer  minimum  resistance  to  the  passage 
of  the  gas  and  means  should  be  provided  for  not  only  breaking  the 
entering  gas  stream  into  smaller  streams,  but  the  capacity  of  the 
muffler  should  be  sufficiently  large  so  that  the  gases  will  expand  to 
nearly  atmospheric  pressure  before  they  are  discharged  into  the  air. 

Various  forms  of  mufflers  are  shown  in  section  at  Fig.  167.  The 
simplest,  outlined  at  A,  consists  of  a  sheet  metal  shell  having  its  ends 
closed  by  cast  metal  pieces.  This  has  several  times  the  volume  of 


Jnlet 


Inlet 


Baffle  Plates 


Inlet 


r 

r 
^ 

W- 

s 

_  ^ 

4 

/ 

,;^x 

•^ 
l 
/ 

/- 
s 

r  •—  ~. 

;  — 

N 

I 

•v 

s 

P: 

\^_ 

i 

/  "*" 
\ 

^^.  _^ 

s»; 

I       ^ 

' 

^ 

V 

\ 

\ 
\ 
\ 
\ 

Spring  Discs 


Outlets 


Fig.  167. — Muffler  Forms  Adapted  to  Reduce  Pressure  of  Exhaust  Gases  Before 

Discharging  Them. 
301 


302  The  Modern  Gasoline  Automobile 

the  cylinder  and  the  gases  expand  to  about  atmospheric  pressure  be- 
fore they  are  discharged  through  the  series  of  small  holes  at  the 
bottom.  The  gas  enters  and  leaves  the  muffler  in  streams  indicated 
by  the  arrows.  The  objection  to  the  use  of  small  holes  for  breaking 
up  the  gas  stream  is  that  these  are  liable  to  clog  with  carbonaceous 
matter  from  the  interior  of  the  engine,  such  as  would  result  when 
excessive  amounts  of  oil  were  used  or  from  mud  or  clay  from  the 
road  surface. 

The  form  shown  at  B  consists  of  a  number  of  concentric  chambers 
which  afford  an  excellent  opportunity  for  the  gas  to  expand  to 
atmospheric  pressure  and  to  break  it  up  thoroughly  before  it  is  dis- 
charged to  the  air.  The  exhaust  gas  enters  the  central  pipe,  passes 
out  through  a  series  of  fairly  large  holes  at  its  extremity  into  the 
middle  compartment  where  it  expands  and  passes  out  through  another 
series  of  holes  into  the  outer  chamber.  Here  it  again  expands  and 
finally  leaves  the  muffler  through  a  series  of  openings  punched  in 
the  outer  shell.  The  course  of  the  gas  may  be  easily  followed  by 
referring  to  the  illustration,  as  it  is  indicated  by  arrows.  A  form 
employing  a  series  of  perforated  baffle  plates  which  divide  the  mulller 
body  into  eight  compartments  is  shown  at  C.  The  function  of  the 
baffles  is  to  break  up  the  gas  by  making  the  gas  streams  follow  a 
devious  path  through  the  first  six  chambers  and  expand  into  the 
seventh  compartment,  from  which  it  passes  to  the  eighth  compartment 
through  a  series  .of  fine  holes  in  the  last  baffle  plate  of  the  series. 

The  form  at  D  consists  of  a  central  pipe  member  around  which  are 
placed  thirteen  pairs  of  stamped  disks  which  form  the  same  number 
of  expansion  chambers.  The  gas  issues  from  the  center  pipe,  where 
opportunity  is  given  it  to  expand  into  the  chambers  provided  by  the 
disks  which  are  merely  placed  in  contact  with  each  other  at  their 
edges  and  helcl  together  by  moderate  pressure.  The  force  of  the 
gas  causes  the  disks  to  spring  slightly  at  their  edges  and  thus  produce 
an  annular  discharge  passage  in  each  set  of  disks  which  insures  thor- 
ough breaking  up  of  the  issuing  gas  stream.  It  is  claimed  that  this 
method  of  construction  provides  a  large  amount  of  cooling  surface  and 
that  the  pressure  of  the  gas  is  reduced  just  as  much  by  the  cooling 
effect  as  it  is  by  the  increase  in  volume  permitted  by  the  expansion 
chambers. 


The  Modern  Gasoline  Automobile  303 

The  form  shown  at  E  is  built  on  the  ejector  principle  and  is 
claimed  to  be  particularly  efficient,  'not'  only  as  relates  to  silencing 
qualities  but  also  because  back  pressure  is  practically  eliminated.  The 
efficiency  is  due  to  its  design,  which  allows  that  part  of  the  gases 
which  pass  through  the  central  pipe  to  do  so  with  considerable  force. 
This  tends  to  produce  a  partial  vacuum,  which  in  turn  promotes  a 
ready  expulsion  of  gas  by  drawing  the  main  portion  through  the 
n  in  filer  rather  than  depend  upon  the  upward  stroke  of  the  piston  to 
clear  both  cylinder  and  muffler.  This  device  is  of  the  baffle  plate 
1vj><>  and  the  partitions  are  in  the  form  of  cones  instead  of  the  usual 
vertical  or  horizontal  dividing  walls  because  the  conical  form  lends 
it  sell!  to  the  ejector  principle  better  than  the  other  types. 


Water  Outlet 


Gas  Outlet 


Water  Inlet 


Fig.  168. — Water-Cooled  Muffler  Used  when  Exceptional  Silence  is  Desired. 
Often  Applied  in  Marine  Service. 

A  very  good  muffler  for  marine  purposes  is  shown  at  Fig.  168. 
This  consists  of  a  double-expansion  chamber  and  a  water  jacket.  If 
the  exhaust  gases  are  cooled  they  will  be  considerably  reduced  in 
volume  and  pressure  and  for  this  reason  water  cooled  forms  are  very 
quiet.  As  the  gases  are  considerably  reduced  in  pressure  by  the  cool- 
ing effect  one  may  use  large  holes  for  the  passage  of  gas  from  one 
chamber  to  the  other  and  the  back  pressure  is  correspondingly  reduced. 
AVliile  a  water  cooled  form  of  muffler  can  be  readi.ly  adapted  to  marine 
service,  it  is  not  possible  to  use  such  on  a  motor  car  because  of 
the  large  volumes  of  water  which  would  have  to  be  supplied  to  insure 
adequate  cooling  of  the  muffling  device. 


304 


The  Modern  Gasoline  Automobile 


It  is  sometimes  possible  to  secure  a  more  prompt  discharge  of  the 
exhaust  gases  from  the  cylinder  if  a  little  attention  is  paid  to  the  de- 
sign of  the  exhaust  manifold.  The  form  shown  at  Fig.  169  is  a  coin- 


Fig.  169. — Suggested  Exhaust  Manifold  in  which  Ejector  Action  of  Exhaust 
Gases  under  High  Velocity  is  Said  to  Reduce  Back  Pressure  on  Pistons. 

posite  member  consisting  of  four  separate  castings,  the  object  of  the 
arrangement  being  to  secure  an  ejector  effect  by  which  the  discharge 
from  any  one  cylinder  would  tend  to  keep  a  condition  of  partial 
vacuum  in  the  manifold  and  thus  draw  out  the  gases.  The  discharge 
from  cylinder  1  goes  through  pipe  A;  that  from  cylinder  2,  through 
member  B,  while  the  gases  from  cylinders  3  and  4  pass  out  through 
pipes  C  and  D  respectively.  If  the  exhausts  occur  in  the  order  1,  2, 
4,  3,  it  will  be  seen  that  the  gases  flowing  through  pipe  A  will  pro- 
duce a  certain  suction  effect  in  pipe  B,  which  will  tend  to  draw  out  the 
gases  discharged  from  that  cylinder  when  the  exhaust  valve  opens. 
A  manifold  so  constructed  is  but  little  more  complicated  than  the 
ordinary  construction,  as  it  consists  of  the  four  bent  tubes  A,  B,  C 
and  D?  which  are  assembled  together  in  such  a  manner  that  a  portion 
of  one  projects  into  the  other.  The  faster  the  engine  works  the  more 
rapid  the  ejection  of  the  gases  and  consequently  the  ejector  action 
has  a  higher  value  at  a  time  that  it  is  needed  the  most.  Such  a  mani- 
fold would  be  more  expensive  than  the  conventional  pattern,  however, 
and  there  might  be  some  difficulty  in  keeping  it  tight  at  the  multi- 
plicity >of  joints. 

Utility  of  Cut-out  Valve  Explained. — In  order  to  take  advantage  of 
the  gain  in  power  which  results  when  the  gases  are  discharged  directly 
into  the  air  instead  of  being  passed  through  the  muffling  device,  mam 


The  Modern  Gasoline  Automobile 


305 


automobile  makers  provide  a  simple  valve,  which  is  called  a  "  cut- 
out," between  the  exhaust  manifold  and  the  muffler.  This  is  arranged 
in  such  a  manner  that  when  opened,  the  gases  are  free  to  issue  directly 
to  the  air  instead  of  passing  through  the  muffling  device,  and  as  the 
back  pressure  incidental  to  the  silencer  is  eliminated  more  power  is 
obtained  from  the  motor.  A  cut-out  is  also  useful  because  it  permits 
one  familiar  with  gasoline  motors  to  detect  irregularity,  in  engine 
operation  by  sound  of  the  exhaust. 

A  typical  cut-out  installation  is  shown  at  Fig.  170,  this  being  more 
efficient  than  that  commonly  used  because  even  with  the  cut-out  valve 


•Main  Muffler 


Fig.  170. — How  Muffler  Cut-out  Valve  is  Arranged  on  Wolseley  (English)  Cars 
to  Reduce  Noisy  Direct  Exhaust. 

opened  the  gases  are  silenced 'to  a  certain  extent  by  being  passed 
through  the  chamber  P  before  they  issue  to  the  air.  When  the  cut-out 
valve  is  closed  the  gases  must  follow  a  circuitous  route  through  the 
muffler  and  by  being  broken  up  and  allowed  to  expand  issue  to  the 


306 


The  Modern  Gasoline  Automobile 


air  without  appreciable  noise.  Whenever  a  cut-out  valve  is  provide( 
it  is  usually  planned  to  open  out  so  that  any  explosion  of  gas  in  tl 
muffler  which  might  result  if  the  motor  missed  several  explosioi 
and  then  fired  the  gas  in  the  silencer  will  tend  to  open  the  valve  and 
relieve  the  excessive  pressure  in  the  muffling  device.  If  some  means 
were  not  provided  to  relieve  the  pressure,  it  might  burst  the  muffler 
asunder.  The  average  cut-out  valve,  therefore,  performs  three  useful 
functions :  First,  it  permits  the  exhaust  gases  to  be  discharged  direct- 
ly to  the  air  at  such  times  that  maximum  motor  power  is  desired; 
second,  it  provides  audible  indication  of  irregular  engine  action; 
third,  it  is  a  safety  or  relief  valve  to  prevent  excessive  pressures  from 
damaging  the  muffler. 


CHAPTER    VI 

Automobile  Power  Plant  Ignition  Systems  Outlined — Chemical  Current  Pro- 
ducers— Mechanical  Generators  of  Electricity — Essentials  of  Battery  Igni- 
tion Systems — Functions  of  Timers  and  Distributors — Operating  Prin- 
ciples of  Induction  Coil — Spark  Plug  Construction  and  Action  Defined — 
Advantages  of  Two- Spark  Ignition — Typical  Battery  Ignition  Groups — 
Low-tension  Ignition  Systems — High-tension  Magneto  Forms — Typical 
Double  Ignition  Systems. 

ONE  of  the  most  important  auxiliary  groups  of  the  gasoline  engine 
comprising  the  automobile  power  plant  and  one  absolutely  necessary 
to  insure  engine  action  is  the  ignition  system  or  the  method  employed 
of  kindling  the  compressed  gas  in  the  cylinder  to  produce  an  explosion 
and  useful  power.  The  ignition  system  has  been  fully  as  well  devel- 
oped as  other  parts  of  the  automobile,  and  at  the  present  time  prac- 
tically all  ignition  systems  follow  principles  which  have  become  stand- 
ard through  wide  acceptance. 

During  the  early  stages  of  development  of  the  automobile  various 
methods  of  exploding  the  charge  of  combustible  gas  in  the  cylinder 
were  employed.  On  some  of  the  earliest  engines  a  flame  burned 
close  to  the  cylinder  head  and  at  the  proper  time  for  ignition,  a  slide 
or  valve  moved  to  provide  an  opening  which  permitted  the  flame  to 
ignite  the  gas  back  of  the  piston.  This  system  was  practical  only  on 
the  primitive  form  of  gas  engines  in  which  the  charge  was  not  com- 
pressed before  ignition.  Later,  when  it  was  found  desirable  to  com- 
press the  gas  a  certain  degree  before  exploding  it,  an  incandescent 
platinum  tube  in  the  combustion  chamber,  which  was  kept  in  a  heated 
condition  by  a  flame  burning  in  it,  exploded  the  gas.  The  naked 
flame  was  not  suitable  in  this  application  because  when  the  slide  was 
opened  to  provide  communication  between  the  flame  and  the  gas  the 
compressed  charge  escaped  from  the  cylinder  with  enough  pressure 
to  blow  out  the  flame  at  times  and  thus  cause  irregular  ignition. 
When  the  flame  was  housed  in  a  platinum  tube  it  was  protected  from 

307 


* 


308  The  Modern  Gasoline  Automobile 

the  direct  action  of  the  gas,  and  as  long  as  the  tube  was  maintained 
at  the  proper  point  of  incandescence  regular  ignition  was  obtained. 

Some  engineers  utilized  the  property  of  gases  firing  themselves 
if  compressed  to  a  sufficient  degree,  while  others  depended  upon  the 
heat  stored  in  the  cylinder  head  to  fire  the  highly  compressed  gas. 
None  of  these  methods  were  practical  in  their  application  to  motor  car 
engines  because  they  did  not  permit  flexible  engine  action  which  is 
so  desirable.  At  the  present  time,  electrical  ignition  systems  in 
which  the  compressed  gas  is  exploded  by  the  heating  value  of  the  mi- 
nute electric  arc  or  spark  in  the  cylinder  are  standard,  and  the  general 
practice  seems  to  be  toward  the  use  of  mechanical  prodi^cers  of  elec- 
tricit}^  rather  than  chemical  batteries. 

Two  general  forms  of  electrical  ignition  systems  may  be  used, 
the  most  popular  being  that  in  which  a  current  of  electricity  under 
high  tension  is  made  to  leap  a  gap  or  air  space  between  the  points 
of  the  sparking  plug  screwed  mto  the  cylinder.  The  other  form, 
which  has  been  almost  entirely  abandoned  in  automobile  practice,  but 
which  is  still  used  to  some  extent  on  marine  engines,  is  called  the  low- 
tension  system  because  current  of  low  voltage  is  used  and  the  spark  is 
produced  by  moving  electrodes  in  the  combustion  chamber. 

The  essential  elements  of  any  electrical  ignition  system,  either 
high  or  low  tension,  are:  First,  a  simple  and  practical  method  of 
current  production;  second,  suitable  timing  apparatus  to  cause  the 
spark  to  occur  at  the  right  point  in  the  cycle  of  engine  action ;  third, 
suitable  wiring  and  other  apparatus  to  convey  the  current  produced 
by  the  generator  to  the  sparking  member  in  the  cylinder. 

The  various  appliances  necessary  to  secure  prompt  ignition  of 
the  compressed  gases  should  be  described  in  some  detail  because  of  the 
importance  of  the  ignition  system.  It  is  patent  that  the  scope  of  a 
work  of  this  character  does  not  permit  one  to  go  fully  into  the  theory 
and  principles  of  operation  of  all  appliances  which  may  be  used  in 
connection  with  gasoline  motor  ignition,  but  at  the  same  time  it  is 
important  that  the  elementary  principles  be  considered  to  some  extent 
in  order,  that  the  reader  should  have  a  proper  understanding  of  the 
very  essential  ignition  apparatus.  The  first  point  considered  will  be 
the  common  methods  of  generating  the  electricity,  then  the  appliances 
to  utilize  it  and  produce  the  required  spark  in  the  cylinder. 


The  Modern  Gasoline  Automobile 


309 


Current  Production  by  Chemical  Action. — The  simplest  method  of 
current  generation  is  by  various  forms  of  chemical  current  producers 
which  may  be  either  primary  or  secondary  in  character.  A  simple 
form  of  cell  is  shown  in  section  at  Fig.  171,  A,  and  as  the  action  of  all 
devices  of  this  character  is  based  on  the  same  principles  it  will  be 


Carbon  Rod 


Terminal 


Connector 


External  Circuit 


Terminal 


Seal 


( 

f-  HE 

j 

Zinc 

Copper  Plate 

±=~   Electrolyte 

°  o    Gas  Bubbles       ° 

o 

f^- 

o 

0 

Depolariztr •- 


B 


Absorb 

-ent 

Lining 


Container 


Fig.  171.— Simple  Primary  Cells  Used  to  Produce  Electric  Current.  A — Form 
to  Show  Principle  of  Current  Production  by  Chemical  Action.  B — Dry  Cell, 
the  Type  Suitable  for  Automobile  Service. 

well  to  consider  the  method  of  producing  electricity  by  the  chemical 
action  of  a  fluid  upon  a  metal.  The  simple  cell  shown  consists  of  a 
container  which  is  filled  with  an  electrolyte  which  may  be  either  an 
alkali  or  acid  solution.  Immersed  in  the  liquid  are  two  plates  of 
metal.,  one  being  of  copper,  the  other  zinc.  A  wire  is  attached  to 
each  plate  by  means  of  suitable  screw  terminals. 

If  the  ends  of  the  plates  which  are  not  immersed  in  the  solution 
are  joined  together  a  chemical  action  will  take  place  between  the 
electrolyte  and  the  zinc  plate  >  in  fact,  any  form  of  cell  consists  of 
dissimilar  elements  which  are  capable  of  conducting  electricity  im- 
mersed in  a  liquid  which  will  act  on  one  of  them  more  than  the 
other.  The  chemical  action  of  electrolyte  on  the  zinc  liberates  gas 
bubbles  which  are  charged  with  electricity  and  which  deposit  them- 


310  The  Modern  Gasoline  Automobile 

selves  on  the  copper  plate.  The  copper  element  serves  merely  as  a 
collecting  member  and  is  termed  the  "  positive  "  plate,  while  the  zinc 
which  is  acted  upon  by  the  solution  is  termed  the  "  negative  "  mem- 
ber. The  flow  of  current  is  from  the  zinc  to  the  copper  plate  througli 
the  electrolyte  and  it  is  returned  from  the  copper  plate  to  the  zinc 
element  by  the  wiring  which  comprises  the  external  circuit. 

While  in  the  cell  shown  zinc  and  copper  are. used,  any  other  combi- 
nation of  metals  between  which  there  exists  a  difference  in  electrical 
condition  when  one  of  them  is  acted  upon  by  a  salt  or  acid  may  be 
employed.  Any  salt  or  acid  solution  will  act  as  an  electrolyte  if  it 
will  combine  chemically  with  one  of  the  elements  and  if  it  does  not 
at  the  same  time  offer  too  great  a  resistance  to  the  passage  of  the 
electric  current.  The  current  strength  will  vary  with  the  nature  of 
the  elements  used,  and  will  have  a  higher  value  when  the  chemical 
action  is  more  pronounced  between  the  negative  member  and  the 
electrolyte. 

As  the  vibrations  which  obtain  when  the  automobile  is  driven  over 
highways  makes  it  difficult  to  use  cells  in  which  there  is  a  surplus  of 
liquid,  a  form  of  cell  has  been  devised  in  which  the  liquid  electrolyte  is 
replaced  by  a  solid  substance  whicty  cannot  splash  out  of  the  container 
even  if  the  cell  is  not  carefully  sealed.  A  current  producer  of  this 
nature  is  depicted  in  section  at  Fig.  171,  B.  This  is  known  as  a  dry' 
cell  and  consists  of  a  zinc  can  in  the  center  of  which  a  carbon  rod  is 
placed.  The  electrolyte  is  held  close  to  the  zinc  or  negative  member 
by  an  absorbent  lining  of  blotting  paper,  and  the  carbon  rod  is  sur- 
rounded by  some  depolarizing  material.  The  top  of  the  cell  is  sealed 
with  pitch  to  prevent  loss  of  depolarizer. 

The  depolarizer  is  needed  that  the  cell  may  continue  to  generate 
current.  When  the  circuit  of  a  simple  cell  is  completed  the  current 
generation  is  brisker  than  after  the  cell  has  been  producing  electricity 
for  a  time.  While  the  cell  has  been  in  action  the  positive  element 
becomes  covered  with  bubbles  of  hydrogen  gas,  which  is  a  poor  con- 
ductor^ of  electricity  and  tends  to  decrease  the  current  output  of 
the  cell.  To  prevent  these  bubbles  from  interfering  with  current 
generation  some  means  must  be  provided  for  disposing  of  the  gas. 
In  dry  cells  the  hydrogen  gas  that  causes  polarization  is  combined 
with  oxygen  gas  evolved  by  the  depolarizing  medium  and  the  combi- 


The  Modern  Gasoline  Automobile 


311 


nation  of  these  two  gases  produces  water  which  does  not  interfere  with 
the  action  of  the  cell.  Carbon  is  used  in  a  dry  cell  instead  of  copper 
because  it  is  a  cheaper  material  and  the  electrolyte  is  a  mixture  of  sal- 
ammoniac  and  chloride  of  zinc  which  is  held  in  intimate  contact 
with  the  zinc  shell  which  forms  the  negative  element  by  the  blotting- 
paper  lining. 


8  Cells  in  Series-Multiple 


Zinc 


Carbon 


Zinc 


Zinc 


Carbon 


12  Cells  in  Series-Mu/tlpIe 


Fig.  172.— Methods  of  Joining  Dry  Cells  to  Form  Batteries  of  Varying  Value. 

A  single  dry  cell  will  not  produce  sufficient  current  to  ignite  the 
charge  of  gas  in  the  engine  cylinder,,  therefore  it  is  common  practice 
to  combine  two  or  more  cells  in  such  a  manner  that  batteries  are 
formed  which  will  give  more  current  than  a  single  cell.  If  it  is  de- 
sired to  increase  the  voltage  the  cells  are  connected  in  series,  as  shown 
at  Fig.  172.  If  one  dry  cell  will  produce  one  and  one  half  volts  and 
six  volts  are  needed  to  produce  the  spark  in  the  engine  cylinder,  the 
current  value  of  one  dry  cell  is  augmented  by  coupling  three  others 
to  it  in  a  series  connection.  When  cells  are  connected  in  series  it  is 
the  unlike  elements  which  are  joined  together.  For  example,  the 


312  The  Modern  Gasoline  Automobile 

zinc  of  one  cell  should  be  joined  with  the  carbon  of  the  adjacent  mem- 
ber by  a  flexible  conductor.  This  will  leave  the  carbon  of  one  end 
cell  and  the  zinc  of  the  other  end  cell  free  so  that  they  can  be  joined 
to  the  apparatus  in  the  outer  circuit. 

When  it  is  desired  to  obtain  more  amperage  or  current  quantity 
than  could  be  obtained  from  a  single  cell  they  are  joined -in  series- 
multiple  connection.  With  this  method  of  wiring  two  or  more  sets 
of  four  cells  which  have  been  joined  in  series  are  used.  The  zinc  of 
one  set  is  joined  with  the  zinc  element  of  the  other  and  the  two  car- 
bons are  similarly  connected.  Any  number  of  sets  of  cells  may  be 
connected  in  series  multiple  and  the  amperage  of  the  combination  is 
increased  proportionately  to  the  number  of  sets  joined  together  in. this 
manner. 

When  dry  cells  are  connected  in  series  the  voltage  of  one  cell  is 
multiplied  by  the  number  of  cells  and  the  amperage  obtained  from  the 
set  is  equal  to  that  of  one  cell.  When  connected  in  series  multiple, 
as  shown  at  Fig.  172,  the  amperage  is  equal  to  two  cells  and  the 
voltage  produced  is  equivalent  to  that  obtained  from  four  cells. 
When  twelve  cells  are  joined  in  series  multiple  the  amperage  is  equal 
to  that  of  one  cell  multiplied  by  three  while  the  voltage  or  current 
pressure  is  equal  to  that  produced  by  one  cell  multiplied  by  the  num- 
ber of  cells  which  are  in  series  in  any  one  set.  By  properly  combin- 
ing dry  cells  in  this  manner  batteries  of  any  desired  current  strength 
may  be  obtained. 

The  terms  "  volt "  and  "  ampere "  are  merely  units  by  which 
current  strength  is  gauged.  The  volt  is  the  unit  of  pressure  or  po- 
tential which  exists  between  the  terminals  of  a  circuit.  The  ampere 
measures  current  quantity  or  flow  and  is  independent  of  the  pressure. 
One  may  have  a  current  of  high  amperage  at  low  potential  or  one 
having  great  pressure  and  but  little  amperage  or  current  strength. 
Voltage  is  necessary  to  overcome  resistance  while  the  amperage  avail- 
able determines  the  heating  value  of  the  current.  As  the  resistance 
to  current  flow  increases  the  voltage  must  be  augmented  proportion- 
ately to  overcome  it.  A  current  having  the  strength  of  one  ampere 
with  a  pressure  of  one  volt  is  said  to  have  a  value  of  one  watt,  which 
is  the  unit  by  which  the  capacity  of  generators  and  the  amount  of 
current  consumption  is  gauged. 


The  Modern  Gasoline  Automobile        /313 

One  of  the  disadvantages  of  primary  cells,  as  those  types  which 
utilize  zinc  as  a  negative  element  are  called,  is  that  the  chemical  action 
produces  deterioration  and  waste  of  material  by  oxidization.  Dry 
cells  are  usually  proportioned  so  that  the  electrolyte  and  depolarizing 
materials  become  weaker  as  the  zinc  is  used  and  when  a  dry  cell  is 
exhausted  it  is  not  profitable  to  attempt  to  recharge  it  because  new 
ones  can  be  obtained  at  a  lower  cost  than  the  expense  of  renewing  the 
worn  elements  would  be. 

The  number  of  dry  cells  necessary  will  vary  with  the  system  of 
ignition  employed  and  the  size  of  the  motor.  While  two  or  three 
cells  will  ignite  small  engines  such  as  used  in  motorcycles,  five  or 
six  will  be  needed  on  automobile  engines  employing  high-tension 
ignition.  When  the  make-and-break  system,  or  low-tension  method, 
is  used  eight  or  ten  cells  are  necessary.  If  the  engine  is  a  multiple 
cylinder  one,  it  will  draw  more  current  than  a  single  cylinder  type 
because  of  the  greater  frequency  of  sparks.  On  four-cylinder  cars 
dry  cells  should  be  joined  in  multiple  series,  which  is  the  most 
economical  arrangement.  Cells  used  in  multiple  connection  are  more 
enduring  than  if  the  same  number  were  used  independently  in  single- 
series  connection.  A  disadvantage  of  a  dry  cell  battery  is  that  it  is 
suited  only  for  intermittent  service  and  it  will  soon  become  exhausted 
if  used  where  the  current  demands  are  severe.  For  this  reason  most 
automobiles  in  which  batteries  are  used  for  ignition  employ  storage  or 
secondary  batteries  to  furnish  the  current  regularly  used  and  a  set 
of  dry  cells  is  provided  for  use  only  in  cases  of  emergency  when  the 
storage  battery  becomes  exhausted. 

Principles  of  Storage  Battery  Construction. — Some  voltaic  couples 
are  reversible,  i.  e.,  they  may  be  recharged  when  they  have  become 
exhausted  by  passing  a  current  of  electricity  through  them  in  a  direc- 
tion opposite  to  that  in  which  the  current  flows  on  discharge.  Such 
batteries  are  known  as  "  accumulators  "  or  "  storage  batteries."  A 
storage  battery  belies  its  name  as  it  does  not  store  current  and  its  action 
is  somewhat  similar  to  that  of  the  simpler  chemical  cell  previously 
described.  In  its  simplest  form  a  storage  cell  would  consist  of  two 
elements  and  an  electrolyte,  as  outlined  at  Fig.  173,  A.  The  storage 
battery  differs  from  the  primary  cell  in  that  the  elements  are  com- 
posed of  the  same  metal  before  charging  takes  place,  usually  lead  in- 


314 


The  Modern  Gasoline  Automobile 


stead  of  being  zinc  or  carbon.  One  of  the  plates  is  termed  the  "  posi- 
tive "  and  may  be  distinguished  from  the  other  because  it  is  brown,  or 
chocolate  in  color  after  charging,  while  the  negative  plate  is  usually 
a  light  gray  or  leaden  color.  The  active  material  of  a  charged  storage 
battery  is  not  metallic  lead  but  oxides  of  that  material. 

T^The  simple  form  shown  at  A  consists  of  two  plates  of  lead  which 
are  rolled  together  separated  by  insulating  bands  of  rubber  at  the  top 


Terminal      Terminal 

•n" 


Gas  Vent 
Terminal 


Handle 


Cover 


inal  Nut 


Lead  Plate  Roll 


Hard  Rubber  Battery  Jar 

Glass  Jar 


Celt 

Partition 
Hard  Rubber 
Separator 
Positive  Plate 


Wood  Separator 


Fig.  173. — Types  of  Accumulators  or  Storage  Batteries.  A — Simple  Form  of 
Cell.  B— Battery  Composed  of  Three  Cells,  Such  as  Commonly  Used  for 
Motor  Car  Engine  Ignition. 

and  bottom  to  keep  them  from  touching.  This  roll  is  immersed  in 
an  electrolyte  composed  of  a  weak  solution  of  sulphuric  acid  in  water. 
Before  such  a  cell  can  be  used  it  must  be  charged,  which  consists 
of  passing  a  current  of  electricity  through  it  until  the  lead  plates 
have  changed  their  nature.  After  the  charging  process  is  compl< 
the  lead  plates  have  become  so  changed  in  nature  that  they  may  be 
considered  as  different  substances  and  a  chemical  action  results  be- 
tween the  negative  plate  and  the  electrolyte  and  produces  current 


The  Modern  Gasoline  Automobile  315 

just  as  in  the  simple  cell  shown  at  Fig.  171,  A.  When  the  cell  is  ex- 
hausted the  plates  return  to  their  metallic  condition  and  are  practically 
the  same,  and  as  there  is  but  little  difference  in  electrical  condition 
existing  between  them,  they  do  not  deliver  any  current  until  electricity 
has  been  passed  through  the  cell  so  as  to  change  the  lead  plates  to 
oxides  of  lead  instead  of  metallic  lead. 

When  storage  cells  are  to  be  used  in  automobile  work  they  are  com- 
bined in  a  single  containing  member,  as  shown  at  Fig.  171,  B,  which 
is  a  part  sectional  view  of  a  Geiszler  storage  battery.  The  main 
containing  member,  a  jar  of  hard  rubber,  is  divided  into  three  parts. 
Each  of  these  compartments  serves  to  hold  the  elements  comprising 
one  cell.  The  positive  and  negative  plates  are  spaced  apart  by  wood 
and  hard  rubber  separators  which  prevent  short  circuiting  between  the 
plates.  After  the  elements  have  been  put  in  place  in  the  compart- 
ments forming  the  individual  cells  of  the  battery,  the  top  of  the  jar 
is  sealed  by  pouring  a  compound  of  pitch  and  rosin,  or  asphaltum, 
over  plates  of  hard  rubber,  which  keeps  the  sealing  material  from 
running  into  the  cells  and  on  the  plates;  Vents  are  provided  over 
each  cell  through  which  gases  produced  by  charging  or  discharging 
are  allowed  to  escape.  These  are  so  formed  that  while  free  passage 
of  gas  is  provided  for,  it  is  not  possible  for  the  electrolyte  to  splash 
out  when  the  vehicle  is  in  motion. 

It  will  be  evident  that  this  method  of  sealing  would  not  be  practical 
on  a  cell  where  the  members  attacked  by  the  acid  had  to  be  replaced 
from  time  to  time,  but  in  a  storage  battery  only  the  electrolyte  need 
be  renewed.  When  the  plates  are  discharged  they  are.  regenerated  by 
passing  a  current  of  electricity  through  them.  New  electrolyte  can 
be  easily  inserted  through  caps  in  which  the  vents  are  screwed.  The 
cells  of  which  a  storage  battery  is  composed  are  joined  together  at 
the  factory  with  bars  of  lead  which  are  burned  in  place  and  only  two 
free  terminals  are  provided  by  which  the  battery  is  coupled  to  the 
outer  circuit. 

The  capacity  of  a  storage  battery  depends  upon  the  size  and  the 
number  of  plates  per  cell,  while  the  potential  orxvoltage  is  determined 
by  the  number  of  cells  joined  in  series  to  form  the  battery.  Each 
cell  has  a  difference  of  potential  of  two  and  two  tenths  volts  when  fully 
charged,  therefore  a  two-cell  battery  will  deliver  a -current  of  four 


316  The  Modern  Gasoline  Automobile 

and  four  tenths  volts  and  a  three-cell  type,,  as  shown  at  Fig.  173,,  B, 
will  give  about  six  and  six  tenths  volts  between  the  terminals.  In 
the  form  shown  each  cell  is  composed  of  four  plates  and  their  sepa- 
rators. Two  of  the  plates  are  positive,  the  remaining  two  negative 
members.  The  size  of  storage  battery  to  be  used  depends  upon  the 
number  of  cylinders  of  the  engine.  Four-cylinder  motors  usually 
take  a  six- volt,  sixty-ampere-hour  battery,  but  it  is  desirable  to  supply 
a  six-volt  battery  having  eighty-ampere-hour  capacity  for  six-cylinder 
motors. 

When  chemical  current  producers  are  depended  upon  to  supply 
the  electricity  used  for  ignition,  two  distinct  sets  are  provided,  one  for 
regular  service  and  the  other  for  emergency  use  in  event  of  failure 
of  that  which  is  depended  upon  regularly.  The  common  practice  is 
to  provide  an  accumulator  or  storage  battery  for  normal  use  and  a  set 
of  dry  cells,  which  are  cheaper  in  first  cost  and  which  do  not  deterio- 
rate if  not  used  for  .some  time,  for  emergency  service.  When  two 
sources  of  current  are  thus  provided,  a  switch  is  included  in  the  cir- 
cuit so  that  either  set  may  be  used  at  will.  The  zinc  terminal 
of  the  dry  battery  and  the  negative  terminal  of  the  storage  battery  are 
joined  together  by  a  suitable  conductor  and  are  grounded  by  running 
the  wire  attached  to  them  to  some  metal  part  of  the  chassis  such  as 
the  crank  case  or  frame  side  member.  The  remaining  terminals, 
which  are  the  positive  of  the  storage  battery  and  the  carbon  of  the 
dry  cell,  are  coupled  to  distinct  terminals  on  the  switch  block. 

The  fact  that  any  battery  cannot  maintain  a  constant  supply  of 
electricity  has  militated  against  their  use  to  a  certain  extent  and 
the  modern  motorist  demands  some  form  of  mechanical  generator 
driven  from  the  power  plant,  which  will  deliver  an  unfailing  supply  of 
electricity.  The  strength  of  batteries  is  reduced  according  to  the 
amount  of  service  they  give.  The  more  they  are  used  the  weaker  they 
become.  The  modern  multiple  cylinder  engines  are  especially  severe 
in  their  requirements  upon  the  current  producer  and  the  rapid  se- 
quence of  explosions  in  the  average  four-  or  six-cylinder  motor  pro- 
duce practically  a  steady  drain  upon  the  battery.  When  dry  cells  are 
used  their  discharge  rate  is  very  low  and  as  they  are  designed  only  for 
intermittent  work,  when  the  conditions  are  such  that  a  constant  flow 
of  current  is  required,  they  are  unsuitable  and  will  soon  deteriorate. 


The  Modern  Gasoline  Automobile  317 

The  same  objection  applies  to  a  certain  extent  to  the  storage  bat- 
tery, though  this  form  of  current  producer  is  more  practical  for  use 
where  a  steady  flow  of  current  is  desired.  The  same  objection  ad- 
vanced against  the  dry  cell  that  the  current  becomes  weaker  as  the 
cell  is  used  applies  equally  well  to  the  storage  battery.  This  has 
made  it  imperative  that  one  of  the  various  forms  of  mechanical  gener- 
ators be  employed  as  a  source  of  electricity  for  regular  ignition  service. 
Such  devices  are  driven  directly  from  the  engine  and  the  amount 
of  energy  they  deliver  is  proportionate  to  the  speed  of  rotation. 
When  the  engine  is  accelerated  and  more  electricity  is  needed,  the 
mechanical  generator  speed  increases  directly  as  that  of  the  driving 
source,  and  more  current  is  delivered  as  the  demands  upon  the  gener- 
ator augment. 

Dynamo  Electric  Machines. — Two  distinct  types  of  mechanical 
generators  are  in  common  use  and  while  their  principles  of  action 
are  practically  the  same,  they  differ  somewhat  in  construction  and 
application.  The  forms  first  used  to  succeed  the  battery  were  modi- 
fications of  the  larger  dynamo  electric  machines  used  for  delivering 
current  for  power  and  lighting.  Later  developments  resulted  in  the 
simplification  of  the  dynamo,  by  which  it  was  made  lighter  and  more 
efficient,  and  the  modern  magneto  igniter  is  the  form  usually  fur- 
nished on  conventional  power  plants.  A  dynamo  uses  electro-mag- 
nets to  produce  a  magnetic  field  for  the  armature  to  revolve  in  and 
is  necessarily  somewhat  heavier  and  larger  than  a  magneto  of  equal 
capacity  because  the  field  in  the  latter  instrument  is  produced  by 
permanent  magnets.  An  important  advantage  in  using  the  magneto 
form  of  construction  is  that  the  weight  of  the  windings  is  saved  be- 
cause the  permanent  magnets  retain  their  magnetism  and  do  not 
require  the  continual  energizing  that  an  electro-magnet  demands. 

The  dynamo  construction  is  superior  where  a  continual  drain  is 
made  upon  the  apparatus,  because  if  a  magneto  is  used  continuously 
the  magnets  are  liable  to  lose  some  of  their  strength  and  as  the 
magnetic  field  existing  between  the  pole  pieces  decreases  in  value  the 
amount  of  current  delivered  by  the  apparatus  diminishes  in  direct 
proportion.  When  electro-magnets  are  used  the  constant  flow  of  elec- 
trical energy  through  the  windings  keeps  them  energized  to  the  proper 
point,  and  as  current  is  continuously  supplied,  the  strength  of  the 


318  The  Modern  Gasoline  Automobile 

magneto  field  remains  constant.  The  dynamo  form  of  generator 
is  utilized  where  currents  of  considerable  value  are  needed  such  as  in 
electric  lighting  systems  now  so  widely  used  on  automobiles. 

Where  the  device  is  depended  upon  only  to  furnish  ignition  cur- 
rent the  magneto  is  preferred  by  most  engineers  because  it  is  simpler 
and  lighter  than  the  dynamo,  and  also  because  it  may  be  made  in  such  • 
form  that  it  will  comprise  a  complete  ignition  system  in  itself.  When 
a  dynamo  is  utilized  the  conditions  are  just  the  same,  as  far  as  neces- 
sary auxiliary  apparatus  is  concerned,  as  though  batteries  were  used 
and  one  merely  substitutes  a  mechanical  generator  in  place  of  the 
chemical  cells.  The  same  auxiliary  apparatus  necessary  in  one  case 
is  employed  in  the  other  as  well. 

A  dynamo  or  magneto  produces  electricity  by  an  inductive  action, 

'  which  is  a  reversal  of  the  phenomena  by  which  a  current  of  electricity 
flowing  around  a  bar  of  iron  or  steel  makes  a  magnet  of  it.  If  a 
wire  through  which  a  current  of  electricity  is  flowing  will  magnetize 
a  bar  of  iron,  a  bar  of  steel  which  is  already  magnetized  will  generate 
a  current  of  electricity  by  induction  in  a  conductor  surrounding  it  if 
either  the  magnet  or  the  coil  of  wire  is  moved  in  such  a  manner  that 
the  magnetic  influence  is  traversed  or  traverses  the  wire.  In  a 
dynamo  or  magneto  a  coil  of  wire  mounted  on  a  suitable  armature  is 
revolved  between  the  pole  pieces  of  the  field  magnet  and  as  the  con- 
ductor cuts  across  the  zone  of  magnetic  influence  a  current  of  elec- 
tricity is  induced  in  the  coil.  The  faster  the  coil  is  rotated  the  more 
rapidly  the  winding  passes  through  the  magnetic  field.  As  an  elec- 
trical impulse  is  produced  every  time  the  magnetic  -field  is  traversed, 
it  is  patent  that  the  greater  number  of  electrical  impulses  will  pro- 

1  duce  a  current  of  higher  value. 

A  sectional  view  of  a  typical  dynamo  electric  machine  of  conven- 
tional design  is  shown  at  Fig.  174.     All  parts  are  clearly  indicated 
and  there  should  be  no  difficulty  in  understanding  the  principles  of  . 
operation.     The  three  main  portions  of  the  dynamo  are  the  field  mag- 
nets, which  produce  the  magnetic  field,  the  armature,  which  carries  • 
the  coils  of  wire  and  which  is  mounted  between  the  extremities  or 
pole  pieces  of  the  magnet,  and  the  brushes,  which  bear  against  segments 
of  a  collecting  device  known  as  a  commutator  serving  to  convey  the 
current  to  terminals  which  are  joined  to  the  outer  circuit.     In  the 


The  Modern  Gasoline  Automobile 


319 


form  shown  the  field  magnets  are  composed  of  a  number  of  iron 
stampings  which  are  surrounded  by  a  coil  of  wire,  and  two  such  mag- 
nets are  provided,  one  above,  the  other  below  the  armature.  The 
armature  "is  supported  on  a  shaft  mounted  in  ball  bearings  so  that  it 
will  turn  with  minimum  friction.  The  whole  mechanism  is  protected 
by  an  outer  casing. 

The  device  shown  is  a  constant  speed  dynamo,  i.  e.,  it  should  be 
operated  at  a  certain  speed  to  obtain  the  best  results.     If  run  faster 


Clutch  Driving  Plate 


Driven  Plate 


Field  Coil 


Ball  Bearings 


Brushes 


Air  Outlet 
Governor  Spring 


Governor  Weight 


Fig.  174. — Gray  &  Davis  Governed  Dynamo,  an  Appliance  for  Producing  Elec- 
tricity by  Mechanical  Means. 

than  the  speed  for  which  it  is  designed  the  excess  current  generated 
is  liable  to  burn  out  the  windings  of  the  field  magnet.  For  this 
reason  a  governor  of  the  fly  ball  type  is  interposed  between  the 
dynamo  armature  and  the  driving  shaft  coupled  to  the  source  of 
power.  At  all  normal  speeds  the  tension  of  the  governor  spring 
keeps  the  two  plates  of  the  clutch  in  contact  and  the  armature  is 
turned  at  the  same  speed  as  the  driving  shaft. 

Should  the  driving  shaft  speed  exceed  a  certain  predetermined 
limit  the  governor  weights  will  fly  out  by  centrifugal  force  and  the 
governor  spring  will  be  compressed  so  the  driving  and  driven  plates 
of  the  clutch  are  separated  and  the  driving  shaft  revolves  independ- 
ently of  the  armature.  As  soon  as  the  armature  speed  becomes  re- 


320 


The  Modern  Gasoline  Automobile 


duced  sufficiently  to  allow  the  governor  spring  to  overcome  the  centrif- 
ugal force  and  draw  back  the  governor  weights,  the  clutch  plates 
are  again  brought  into  contact  and  the  armature  is  again  joined  to 
the  driving  shaft. 

A  current  of  air  is  kept  circulating  through  the  casing  by  means 
of  the  fan  action  of  the  reenforcing  webs  of  the  clutch  plate,  the  ob- 


Flywheel 


Transmission. 


Magnets 


Coils 


Fig.  176. — Distinctive  Form  of  Current  Producer  Used  on  Ford  Cars  is  Incc 
porated  in  the  Power  Plant  Fly  Wheel. 

ject  being  to  absorb  any  heat  which  may  be  produced  while  th( 
dynarrro  is  in  action.  An  appliance  of  this  nature  may  be  driven 
frdm  the  engine  by  belt,  chain,  or  gear  connection;  It  will  deliver 
low  voltage  current  which  must  be  transformed  by  means  of  an  induc- 
tion coil  to  current  of  higher  value  in  order  that  it  may  be  success- 


The  Modern  Gasoline  Automobile  321 

fully  utilized  to  produce  the  spark  in  the  combustion  chambers  of  the 
engine. 

A  very  ingenious  application  of  the  dynamo  is  shown  at  Fig.  175. 
The  electric  generator  is  built  in  such  a  manner  that  it  forms  an 
integral  part  of  the  power  plant.  The  magneto  field  is  produced  by 
a  series  of  revolving  magnets  which  are  joined  to  and  turn  with  the 
fly  wheel  of  the  motor.  The  armature  coils  are  carried  by  a  fixed 
plate  which  is  attached  to  the  engine  base.  This  apparatus  is  really  a 
magneto  having  a  revolving  field  and  a  fixed  armature,  and  as  the 
magnets  are  driven  from  the  fly  wheel  there  is  no  driving  connection 
to  get  out  of  order  and  cause  trouble.  As  the  coils  in  which  the 
current  is  generated  are  stationary,  no  commutator  or  brushes  are 
needed  to  collect  the  current  because  the  electricity  may  be  easily 
taken  from  the  fixed  coils  by  direct  connection.  It  has  been  ad- 
vanced that  this  form  of  magneto  is  not  as  efficient  as  the  conventional 
patterns  because  more  metal  and  wire  are  needed  to  produce  the  cur- 
rent required.  As  the  magnets  which  form  the  heavier  portion  of  the 
apparatus  are  joined  to  the  fly  wheel,  which  can  be  correspondingly 
lighter,  this  disadvantage  is  not  one  that  can  be  considered  seriously 
because  the  magnet  weight  is  added  to  that  of  the  motor  fly  wheel, 
the  combined  weight  of  the  two  being  that  of  an  ordinary  balance 
member  used  on  any  other  engine  of  equal  power. 

Timer  and  Distributor  Forms. — Anyone  familiar  with  the  basic 
principles  of  internal  combustion  engine  action  will  recognize  the  : 
need  of  incorporating  some  device  in  the  ignition  system,  which  will 
insure  that  the  igniting  spark  will  occur  only  in  the  cylinder 
that  is  ready  to  be  fired  and  at  the  right  time  in  the  cycle  of  opera- 
tions. There  is  a  certain  definite  point  at  which  the  spark  must  take 
place,  this  having  been  determined  to  be  at  the  end  of  the  compres- 
sion upstroke,  at  which  time  the  gas  has  been  properly  compacted 
and  the  piston  is  about  to  start  returning  to  the  bottom  of  the  cyl- 
inder again.  Timers  or  distributors  are  a  form  of  switch  designed 
so  that  hundreds  of  positive  contacts  which  are  necessary  to  close  and 
open  the  circuit  may  be  made  per  minute  without  failure. 

When  the  device  is  employed  to  open  and  close  a  low-tension  cir-J 
cuit,  it  is  known  as  a  commutator  or  timer,  and  when  used  in  connec-  / 
tion  with  current  of  high  voltage  they  are  called  secondary  distribu- 


322  The  Modern  Gasoline  Automobile 

tors.  Certain  constructional  details  make  one  form  different  from 
the  other,  and  while  they  perform  the  same  functions  they  vary  in 
design.  Such  distributing  devices  are  always  driven  by  positive  gear- 
ing from  the  engine  and  are  timed  so  the  sparks  will  occur  in  the 
cylinders  at  just  the  proper  ignition  time.  The  usual  construction  is 
to  use  a  fixed  case  which  carries  one  or  more  contact  members  suitably 
disposed  around  its  periphery  and  a  central  revolving  member  or 
cam  which  contacts  with  the  points  on  the  body  of  the  device  to  close 
any  desired  circuit.  On  a  four-cycle  engine  the  cam  is  revolved  at 
one  half  the  engine  speed  and  the  timer  is  usually  driven  from  the 
cam  shaft.  In  two-cycle  engines  the  revolving  member  of  the  timer 
turns  at  engine  speed,  and  should  be  driven  directly  from  and  at 
the  same  speed  as  the  crank  shaft. 

Simple  timer  forms  suitable  for  one-cylinder  motors  are  shown 
at  Fig.  175.     The  simplest  one,  depicted  at  A,  consists  of  a  rocking 
member  of  fiber  or  other  insulating  material  which  carries  a  steel 
spring  that  is  normally  out  of  engagement  with  the  surface  of  the 
cam.     When  the  point  of  the  cam  brushes  by  the  contact  spring,  any 
circuit  in  which  the  device  is  incorporated  will  be  closed  and  current 
will  flow  from  the  battery  or  dynamo  to  the  transformer  coils  and 
spark  plugs  which  are  depended  on  to  furnish  a  spark  of  sufficient 
intensity  to  insure  ignition  of  the  gas.     It  is  desirable  that  the  mem- 
ber which  carries  the  contact  spring  be  capable  of  a  certain  degree  of 
movement,  in  order  that  the  spark  time  may  be  advanced  or  retard* 
to  suit  various  running  conditions.     In  the  form  shown  if  the  to] 
of  the  casing  is  pushed  in  the  direction  of  the  arrow,  the  contac 
spring  will  come  in  contact  with  the  point  of  the  cam  which  is  turn- 
ing in  the  direction  indicated  sooner  than"  it  will  if  the  base  membei 
is  rocked  in  a'  reverse  direction  and  the  contact  spring  pulled  awaj 
from  the  point  of  the  cam  instead  of  being  moved  forward  to  meet  il 
The  wipe  contact  form  is  the  simplest,  but  the  spring  is  liable 
wear  at  the  point  of  contact  and  may  break  off  and  cause  trouble 
Such  a  device  is  more  suitable  for  low-speed  engines  than  it  is  f( 
those  which  have  high  crank-shaft  velocity. 

The  single-cylinder  timer  depicted  at  B  is  a  form  that  is  widob 
used  on  high-speed  engines  and  contact  is  made  between  a  pair  ol 
platinum  contact  points  which  just  touch  each  other  instead  of  wi] 


The  Modern  Gasoline  Automobile 


323 


ing.  Platinum  is  a  material  that  is  not  affected  by  the  arcing  or  heat 
of  the  spark  as  much  as  steel  or  brass  would  be  and  provides  a  more 
positive  contact.  In  the  wipe  contact  form  the  continual  brushing 
action  of  the  cam  against  the  spring  tends  to  keep  the  contact  surfaces 
clean,  but  this  condition  does  not  obtain  in  the  simple  touch  contact 
of  the  form  shown  at  B.  The  casing  is  rocked  in  the  direction  of 


Contact 
Spring 


Contact  Points. 


B 


Fig.  176. — Simple  Forms  of  Contact  Breakers  Used  on  One-Cylinder  Engines. 
A — Wipe  Contact.    B— Touch  Contact. 

the  arrow  to  advance  a  spark  in  either  case.  The  form  shown  at  B  is 
more  economical  of  current  because  the  contact  is  shorter  and  is  more 
suitable  for  high-speed  engines.  While  the  forms  considered  prove 
practical  in  their  application  to  simple  one-  and  two-cylinder  engine 
forms,  they  are  very  heavy  or  clumsy  appliances  when  used  for  four- 
T  cylinder  engines,  as  it  is  very  hard  to  assemble  the  spring  elenient  so 
that  the  contact  will  take  place  at  the  proper  point  in  all  cylinders. 

When  a  timer  is  to  be  used  in  connection  with  a  four-  or  six-cylin- 
der engine  the  compact  form  shown  at  Fig.  177,  A,  is  usually  adopted. 
This  has  many  desirable  features  and  permits  of  timing  the  spark 
with  great  accuracy.  The  contact  segments  are  spaced  on  quarters 
and  are  imbedded  in  a  ring  of  fiber  which  is  retained  in  a  casing  of 


324 


The  Modern  Gasoline  Automobile 


aluminum.  The  central  revolving  element  carries  a  lever  which 
has  a  roll  at  one  end  and  a  tension  spring  designed  to  keep  the  roller 
in  contact  with  the  inner  periphery  of  the  fiber  ring  at  the  other. 
The  segments  are  of  steel  and  are  accurately  machined  and  hardened, 


High  Tension 
Terminal 


To  Plug 


Segment 


Revolving 
Member 


Hole  for 
Drive  Shaft 


Fig.  177.— Timers  Employed  on  Four-Cylinder  Engines.  A— Four-Contact 
Device  for  Commutating  Primary  Current.  B — Combined  Timer  and  Dis- 
tributor Directs  Both  High-  and  Low-Tension  Energy. 

and  as  the  surface  of  the  roller  is  also  hardened,  this  form  of  tinier  is 
widely  used  because  it  provides  a  positive  contact  and  works  smoothly 
at  all  engine  speeds. 

A  secondary  distributor  which  is  employed  to  distribute  both  high- 
and  low-tension  current  is  shown  at  Fig.  177,  B.     This  consists  of 
primary  timing  arrangement  in  the  lower  portion,  and  a  second ar 
current-distributing  segment  at  the  upper  portion.     The  central 
volving"  member  carries  as  many  rolls  as  there  are  cylinders  to 
fired,  these  being  spaced  at  the  proper  points  in  the  circle  to  insui 
correct  timing.     One  primary  contact  member  is  screwed  into  tht 
casing,  this  contacting  with  the  rolls  as  they  revolve.     At  the  uppei 


The  Modern  Gasoline  Automobile. 


325 


portion  of  the  case  a  number  of  terminals  are  inserted  from  which 
wires  lead  to  plugs  in  the  cylinders.  When  a  timer  of  the  form 
si  town,  at  Fig.  177,  A,  is  used,  a  separate  injiujcjioji^ml  is  needed  for 
cadi  cylinder  and  the  number  of  units  in  the  coil  box  and  contact 
points  on  the  timer  will  be  the  same  as  the  number  of  cylinders  to  be 
lired.  When  a  secondary  distributor  is  employed  but  one  induction 
coil  is  needed  for  all  cylinders,  because  the  secondary  or  high-tension 
current  from  one  unit  is  distributed  to  the  spark  plugs  at  the  proper 
time.  Various  wiring  diagrams  will  be  presented  to  show  the 
methods  of  using  timers  and  distributors.  It  will  be  noticed  that 
the  high-tension  portion  of  the  distributor  is  well  insulated  from  the 
primary  circuit  closing  member  at  the  lower  end.  This  is  necessary 
because  current  of  high  voltage  is  much  more  difficult  to  handle  than 
that  of  lower  pressure,  and  it  is  more  liable  to  short  circuit. 

The  arrangement  of  the  contact  points  for  various  numbers  of 
cylinders  in  roller  contact  timers  is  shown  at  Fig.  178.     At  A  but 


Fig.  178. — Showing  Disposition  of  Contact  Points  on  Timers  for  Number  of 
Cylinders.  A — One-Cylinder  Type.  B — Arrangement  for  Two-Cylinder 
Opposed  Motor.  C — Contacts  Separated  by  90  Degrees  in  One  Direction 
and  270  Degrees  in  the  Other  when  Used  on  Two-Cylinder  Vertical  Engine 
with  Opposed  Crank  Pins.  D — Three-Cylinder  Form.  E — Suitable  for 
Four-Cylinder  Engines.  F — Type  Employed  on  Six-Cylinder  Power  Plants. 


326  The  Modern  Gasoline  Automobile 

one  segment  is  provided,  this  obviously  serving  only  one  cylinder. 
The  form  depicted  at  B  is  utilized  with  a  double-cylinder  opposed 
motor  or  a  twin-cylinder  vertical  type  in  which  both  connecting  rods 
act  on  a  common  crank  pin  or  crank  pins  in  the  same  plane.  As  the 
explosions  are  evenly  spaced  and  the  intervals  separating  the  sparks 
are  equal,  the  contact  segments  are  placed  diametrically  opposite  and 
are  separated  by  a  space  of  180  degrees.  If  the  two-cylinder  engine 
is  a  vertical  form  having  opposed  cranks,  the  explosions  will  not 
be  separated  by  equal  intervals,  so  the  segments  must  be  placed  to  com- 
pensate for  the  difference  which  exists  in  the  time  interval  separating 
the  -power  impulses.  Two  contact  segments  are  imbedded  in  the  in- 
sulating ring,  the  contacts  being  separated  by  a  space  of  90  degrees 
on  one  side  and  270  degrees  on  the  other.  This  form  of  timer  is 
seldom  used  at  the  present  time  because  the  two-cylinder  engine  of 
the  pattern  for  which  it  is  adapted  has  been  practically  discarded. 

When  three  cylinders  are  used  the  contact  points  are  separated 
by  a  space  of  120  degrees,  as  shown  at  D.  In  a  four-cylinder  timer 
the  contact  segments  are  spaced  on  quarters  of  the  circle  and  are 
separated  by  a  space  equal  to  90  degrees.  With  a  six-cylinder  motor 
six  segments  are  necessary,  these  being  separated  by  a  space  of  60 
degrees,  as  shown  at  F.  Before  considering  the  other  components  of 
a  battery  ignition  system  it  would  be  well  to  outline  the  essential 
elements  of  a  simple  ignition  group  so  that  the  circuit  and  flow  of 
current  may  be  easily  followed. 

,'  Essential  Elements  of  Simple  Ignition  System. — The  current  ob- 
tained from  the  dry  or  storage  battery  or  low-tension  dynamo  or 
magneto  is  not  sufficiently  powerful  to  leap  the  gap  which  exists  be- 
tween the  points  of  the  spark  plug  in  the  cylinder  unless  it  is  trans- 
formed to  a  current  having  a  higher  potential.  The  air  gap  between 
the  points  of  the  spark  plug  has  a  resistance  which  requires  several 
thousand  volts  pressure  to  overcome,  and  as  a  battery  will  only  deliver 
six  to  eight  volts,  it  will  be  evident  that,  unless  the  current  value 
is  increased,  it  could  not  produce  a  spark  between  the  plug  elec- 
trodes. 

The  low  voltage  current  is  transformed  to  one  of  higher  potential 
by  means  of  a  device  known  as  the  induction  coil.  The  current  from 
the  battery  is  passed  through  the  primary  coil,  which  is  composed  of 


The  Modern  Gasoline  Automobile 


327 


several  layers  of  coarse  wire  wound  around  a  core  of  soft  iron  wire 
to  form  an  electro-magnet  as  shown  at  Fig.  179.  Surrounding  this 
primary  coil  is  one  composed  of  a  large  number  of  turns  of  finer 


mr- 

-mm 

i   Vibrator 

Platinum     -• 

!  ^  Screw 

/ 

J           Points  \Jj 

f 

-| 

ibler  Blade/'  lUH  ' 

mm 

Hi 

/Secondary  Coil 


Ground 


Fig.  179. — Simple  Ignition  System  for  One-Cylinder  Motor  Showing  Important 
Components  and  Their  Relation  to  Each  Other. 


328  The  Modern  Gasoline  Automobile 

conductor.  When  a  current  of  electricity  of  low  voltage  passes 
through  the  primary  coil,  a  current  of  very  high  electron-motive  force 
is  produced  in  the  secondary  winding.  One  end  of  each  coil  is 
grounded.  The  free  end  of  the  primary  coil  is  coupled  to  the  battery 
while  that  of  the  secondary  coil  is  attached  to  the  insulated  terminal 
of  the  spark  plug. 

The  arrangement  of  wiring  at  Fig.  179  is  that  employed  in  a 
typical  transformer  coil  which  is  used  to  increase  the  voltage  of  the 
current  sufficiently  to  cause  it  to  overcome  the  resistance  of  the  air 
gap  at  the  spark  plug  and  produce  a  spark  which  will  ignite  the  gas. 
In  the  primary  circuit  are  included  a  suitable  timer  for  closing  the 
circuit,  a  battery  of  chemical  cells  to  supply  the  energizing  current, 
and  a  vibrator  or  make-and-break  mechanism  on  the  coil.  The  sec- 
ondary circuit  includes  the  spark  plug  and  the  secondary  winding 
of  the  coil. 

When  the  primary  circuit  is  closed  by  the  cam  of  the  timer  making 
contact  with  the  segment,  the  current  from  the  battery  flows  through 
the  primary  coil  of  the  transformer.  This  magnetizes  the  core  which 
draws  down  the  trembler  bk/le,  this  in  turn  separating  the  platinum 
contact  point  of  the  vibrator  and  interrupting  the  current.  As  soon 
as  the  current  is  interrupted  at  the  vibrator  the  core  ceases  to  be  a 
magnet  and  the  trembler  blade  flies  back  and  once  again  closes  the 
circuit  between  the  platinum  points.  Every  time  the  circuit  is  made 
and  broken  at  the  vibrator  an  electrical  impulse  is  induced  in  the 
secondary  winding  of  the  coil. 

The  vibrator  may  be  adjusted  so  that  it  will  make  and  break  the 
circuit  many  times  a  minute  and  as  a  current  of  high  potential  is 
produced  in  the  secondary  winding  with  each  impulse,  a  small  spark 
will  be  produced  between  the  points  of  the  spark  plug.  The  condenser 
is  a  device  composed  of  layers  of  tin  foil  separated  from  each  other 
by  waxed  or  varnished  paper  insulation.  It  is  utilized  to  absorb  some 
of  the  excess  current  produced  between  the  vibrator  points,  which 
causes  sparking.  This  extra  current  is  induced  by  the  action  of  the. 
primary  coils  of  wire  upon  each  other  and  by  a  reversed  induction  in- 
fluence from  the  secondary  coil. 

If  this  current  is  not  taken  care  of,  it  will  impede  the  passage 
of  the  primary  current  and  the  sparks  are  apt  to  burn  or  pit  the 


The  Modern  Gasoline  Automobile 


329 


platinum  contact  points  of  the  vibrator.  When  a  condenser  is  pro- 
vided the  extra  primary  current  is  absorbed  by  the  sheets  of  tin  foil 
which  become  charged  with  electricity.  When  contact  is  made  again 
the  condenser  discharges  the  current  in  the  same  direction  as  that 
flowing  through  the  primary  coil  from  the  battery  and  the  value 
of  the  latter  is  increased  proportionately.  There  is  less  sparking  be- 
tween the  vibrator  points  and  a  stronger  current  is  induced  in  the 
secondary  coil  which  in  turn  produces  a  more  intense  spark  between 
the  points  of  the  spark  plug. 

A  typical  induction  coil  such  as  would  be  used  for  firing  a  one- 
cylinder  engine  if  used  with  a  simple  timer,  or  a  multiple-cylinder 


To  Battery 


Spring  Adjustment 


I 


Fig.  180. — Part  Sectional  View  of  Simple  Induction  Coil,  an  Important  Component 
of  All  Battery  Ignition  Groups  and  Sometimes  Used  with  Magnetos. 

engine  if  used  in  connection  with  a  combined  timer  and  distributor,  is 
depicted  in  part  section  at  Fig.  180.  It  will  be  observed  that  three 
terminal  screws  are  provided  on  the  box,  one  designed  to  be  attached 
to  the  battery,  the  other  two  to  the  spark  plug  and  ground,  respec- 
tively. The  terminal  to  which  the  battery  wire  is  attached  is  coupled 
to  the  bridge  member  which  carries  the  contact  screw  while  the  vi- 


330  The  Modern  Gasoline  Automobile 

brator  blade  is  connected  with  one  of  the  ends  of  the  primary  coil. 
The  other  end  of  the  primary  coil  goes  to  the  terminal  which  is  joined 
to  the  ground.  The  condenser  is  shunted  in  between  the  vibrator 
points,  i.  e.,  one  of  the  leads  is  attached  to  terminal  No.  1  while  the 
other  is  soldered  to  the  end  of  the  primary  coil  which  goes  on  the 
vibrator  spring  member.  One  end  of  the  secondary  coil  is  attached 
to  terminal  No.  2,  which  is  grounded  on  some  metal  part  of  the 
chassis  frame,  while  the  other  end  is  secured  to  terminal  No.  3,  which 
is  joined  to  the  spark  plug  electrode.  After  the  various  components 
of  the  induction  coil  are  assembled  in  the  box  and  the  connections 
made  as  indicated,  the  spaces  between  the  sides  of  the  box  and  the 
coil  member  are  filled  with  an  insulating  compound  composed  of  bees- 
wax, pitch  and  rosin.  This  holds  everything  rigidly  in  place  and 
prevents  the  wire  joints  loosening  through  vibration. 

The  method  of  connecting  the  members  of  an  induction  coil,  shown 
at  Fig.  180,  is  a  conventional  one,  though  the  connections  will  differ 
with  the  nature  of  the  circuit  of  which  the  coil  forms  a  part  and  the 
number  of  units  comprising  the  coil  assembly.  When  such  devices 
are  employed  for  igniting  multiple-cylinder  motors,  the  internal 
wiring  is  very  much  the  same  as  though  the  same  number  of  box 
coils  for  single-cylinder  ignition  were  combined  together  by  outside 
conductors.  The  number  of  terminals  provided  will  vary  with  the 
number  of  units. 

Various  forms  of  induction  coils  are  depicted  at  Fig.  181.  That 
at  A  is  a  simple  unit  form  in  which  the  coil  is  attached  directly  to 
the  spark  plug,  which  in  turn  is  screwed  into  the  cylinder.  On  this 
coil  but  two  primary  terminals  are  attached,  one  being  connected  to 
the  insulated  contact  point  on  the  timer,  the  other  being  grounded, 
or  attached  to  the  battery.  Coils  of  this  type  have  been  very  popular 
in  marine  application  because  of  the  simple  and  direct  wiring  possible, 
but  they  have  not  been  used  in  connection  with  automobile  engine 
ignition  to  any  extent.  The  form  shown  at  B  is  a  simple  dash  coil 
for  one-cylinder  use  which  has  three  terminals,  one  being  used  for  a 
secondary  lead  to  the  spark  plug,  the  other  two  being  joined  to  the 
battery  and  ground  respectively,  as  shown  at  Fig.  180. 

The  form  of  coil  shown  at  C  is  a  two-unit  member  designed  for 
double-cylinder  ignition.  As  the  switch  is  mounted  on  the  coil  box 


The  Modern  Gasoline  Automobile 


331 


to  use  two  sets  of  batteries,  six  terminals  are  provided  on  the  bottom 
of  the  coil  case.     Two  of  these  are  attached  directly  to  the  insulated 


Fig.  181.— Conventional  Induction  Coil  Forms.  A— Coil  Unit  and  Plug  Com- 
bined. B— Simple  Box  Coil  for  One-Cylinder  Ignition.  C— Two-Unit  Coil 
for  Two-Cylinder  Motors.  D — Four-Unit  Coil  for  Four-Cylinder  Service. 


332  The  Modern  Gasoline  Automobile 

contact  point  of  the  timer;  two  others  which  are  enclosed  in  hard, 
rubber  insulating  caps  are  attached  to  the  spark  plugs.  The  two  imme- 
diately under  the  switch  are  attached  to  the  free  terminals  of  the  bat- 
tery, two  sets  being  provided,  one  being  coupled  to  each  side  of  the 
switch. 

With  a  four-unit  coil,  as  shown  at  D,  ten  terminals  are  provided 
because  of  the  attached  switch.  Four  go  to  the  spark  plugs,  four  to 
the  insulated  segments  of  the  timer  and  two  to  the  battery,  or  battery 
and  magneto  or  dynamo,  as  the  case  may  be.  In  modern  coils  the 
units  may  be  removed  from  the  box  without  disturbing  any  internal 
connection,  and  a  new  one  slipped  in  its  place  if  it  does  not  function 
properly.  Special  care  is  taken  in  insulating  the  high-tension  ter- 
minal by  means  of  rubber  caps  which  surround  the  wire,  and  care  is 
taken  to  have  the  vibrator  contact  points  readily  accessible  for  in- 
spection, cleaning,  or  adjustment. 

Spark  Plug  Design  and  Application. — With  the  high-tension  system 
of  ignition  the  spark  is  produced  by  a  current  of  high  voltage  jump- 
ing between  two  points  which  break  the  complete  circuit,  which  would 
exist  otherwise  in  the  secondary  coil  and  its  external  connections. 
•The  spark  plug  is  a  simple  device  which  consists  of  two  terminal 
electrodes  carried  in  a  suitable  shell  member,  which  is  screwed  into 
the  cylinder.  Typical  spark  plugs  are  shown  in  section  at  Fig.  182 
and  the  construction  can  be  easily  understood.  The  secondary  wire 
from  the  coil  is  attached  to  a  terminal  at  the  top  of  a  central  electrode 
member,  which  is  supported  in  a  bushing  of  some  form  of  insulating 
material.  The  type  shown  at  A  employs  a  molded  porcelain  as  an 
insulator,  while  that  depicted  at  B  uses  a  bushing  of  mica.  The  in- 
sulating bushing  and  electrode  are  housed  in  a  steel  body,  which  is 
provided  with  a  screw  thread  at  the  bottom,  by  which  it  is  screwed 
into  the  combustion  chamber. 

When  porcelain  is  used  as  an  insulating  material  it  is  kept  from 
direct  contact  with  the  metal  portion  by  some  form  of  yielding  pack- 
ing, usually  asbestos.  This  is  necessary  because  the  steel  and  porce- 
lain have  different  coefficients  of  expansion  and  some  flexibility  must 
be  provided,  at  the  joints  to  permit  the  materials  to  expand  differently 
when  heated.  The  steel  body  of  the  plug  which  is  screwed  into  the 
cylinder  is  in  metallic  contact  with  it  and  carries  sparking  points 


The  Modern  Gasoline  Automobile 


333 


which  form  one  of  the  terminals  of  the  air  gap  over  which  the  spark 
occurs.  The  current  entering  at  the  top  of  the  plug  cannot  reach 
the  ground,  which  is  represented  by  the  metal  portion  of  the  engine, 
until  it  has  traversed  the  full  length  of  the  central  electrode  and 
overcome  the  resistance  of  the  gap  between  it  and  the  terminal  point 
on  the  shell.  The  porcelain  bushing  is  firmly  seated  against  the 


Spring  Washer 


Spring  to  Allow 
for  Expansion 
and  Contraction 


Standard 
Thread 


Solid  Nlchel  Rod. 


Terminal 


Mica 


Brass  Screw  \, 
Gland 


Electrode 


B 


Fig.  182.— Spark  Plug  Construction  OutMned.     A— Sectional  View  of  Porcelain 
Plug.     B— Part  Sectional  View  of  Mica  Plug. 

asbestos  packing  by  means  of  a  brass  screw  gland  which  sets  against  a 
flange  formed  on  the  porcelain,  and  which  screws  into  a  thread  at 
the  upper  portion  of  the  plug  body. 

The  mica  plug  shown  at  B  is  somewhat  simpler  in  construction 
than  that  shown  at  A.  The  mica  core  which  keeps  the  central  elec- 
trode separated  from  the  steel  body  is  composed  of  several  layers  of 
pure  sheet  mica  wound  around  the  steel  rod  longitudinally,  and  hun- 
dreds of  stamped  steel  washers  which  are  forced  over  this  member 


334 


The  Modern  Gasoline  Automobile 


and  compacted  under  high  pressure  with  some  form  of  a  binding 
material  between  them.  Porcelain  insulators  are  usually  molded 
from  high  grade  clay  and  are  approximately  of  the  shapes  desired 
by  the  designers  of  the  plug.  The  central  electrode  may  be  held  in 


Terminal 


Porcelain 


'land 


Gland 


Electrode 


Spark  Points 


Spark  Points 


Fig.  183.— Three  Forms  of  Spark  Plugs  in  which  Electrodes  are  Separated  by 

Porcelain  Insulation. 

place  by  mechanical  means  such  as  nuts,  packings,  and  a  shoulder 
on  the  rod,  as  shown  at  A.  Another  method  sometimes  used  is  to 
cement  the  electrode  in  place  by  means  of  some  form  of  fire-clay 
cement.  Whatever,  method  of  fastening  is  used,  it  is  imperative  that 
the  joints  be  absolutely  tight  so  that  no  gas  can  escape  at  the  time 
of  explosion.  With  a  mica  plug  the  electrode  and  the  insulating 
bushing  are  really  a  unit  construction  and  are  assembled  in  permanent 
assembly  at  the  time  the  plug  is  made. 

Other   insulating    materials   sometimes    used    are    glass,    steatite 
(which  is  a  form  of  soapstone),  and  lava.     Mica  and  porcelain  are 


The  Modern  Gasoline  Automobile 


335 


the  two  common  materials  used  because  they  give  the  best  results. 
Glass  is  liable  to  crack  while  lava  or  the  soapstone  insulating  bushings 
absorb  oil.  The  spark  gap  of  the  average  plug  is  equal  to  about  ^ 
of  an  inch  for  coil  ignition  and  from  -^  to  -fa  of  an  inch  when 
used  in  magneto  circuits.  A  simple  gauge  for  determining  the  gap 
setting  is  the  thickness  of  an  ordinary  visiting  card  for  magneto 
plugs,  or  a  space  equal  to  the  thickness  of  a  worn  dime  for  a  coil  plug. 
The  insulating  bushings  are  made  in  a  number  of  different  ways,  and 
while  details  of  construction  vary,  spark  plugs  do  not  differ  essen- 
tially in  design.  Three  different  forms  of  plugs  using  porcelain  insu- 
lation are  shown  in  part  section  at  Fig.  183.  Porcelain  is  the  ma- 
terial most  widely  used  because  it  can  be  glazed  so  that  it  will  not 
absorb  oil,  and  it  is  subjected  to  such  high  temperature  in  baking 
that  it  is  not  liable  to  crack  when  heated. 

The  spark  plugs  may  be  screwed  into  any  convenient  part  of  the 
combustion  chamber,  the  general  practice  being  to  install  them  in  the 


Wire 


Pocket/ 


Electrodes—  fe^ 


Recess 


Fig.  184. — Methods  of  Installing  Spark  Plugs  of  Conventional  Form.  A — In- 
correct Method.  B — Correct  Installation  in  Valve  Chamber  Cap.  C — 
Combined  with  Cylinder  Priming  Device  or  Compression  Relief  Cock. 

caps  over  the  inlet  valves,  or  in  the  side  of  the  combustion  chamber,  so 
the  points  will  be  directly  in  the  path  of  the  entering  fresh  gases 
from  the  carburetor.  The  methods  of  spark  plug  installation  com- 
monly used  are  shown  at  Fig.  184.  At  A  the  plug  is  screwed  into 
a  threaded  hole  which  passes  through  the  valve  cap  in  such  a  manner 


336  The  Modern  Gasoline  Automobile 

that  the  points  are  in  a  pocket.  This  is  not  considered  to  be  as  good 
as  the  method  depicted  at  B,  where  the  interior  of  the  valve  cap  is 
recessed  out  so  there  is  considerable  space  around  the  spark  point. 
When  the  electrodes  are  carried  in  a  pocket  they  are  more  liable  to 
become  short  circuited  by  oil  or  carbon  accumulations,  because  it  is 
difficult  for  the  fresh  gases- to  reach  them  and  the  pocket  tends  to 
retain  heat.  Ignition  is  not  so  certain  because  some  of  the  burned 
gases  may  be  retained  in  the  pocket  and  prevent  the  fresh  gas  from 
getting  in  around  the  spark  gap.  With  a  recess,  as  shown  at  B,  condi- 
tions are  more  favorable  because  the  fresh  gases  can  sweep  the  points 
of  the  spark  plug  and  keep  them  clear,  and  also  because  of  the 
larger  space  any  burned  products  retained  in  the  cylinder  are  not  so 
apt  to  collect  around  the  plug  point. 

On  some  types  of  engines  which  are  not  provided  with  compression 
relief,  or  priming  cocks,  plugs  are  sometimes  installed,  as  shown  at  C. 
A  special  fitting,  which  carries  a  priming  cup  at  one  side,  is  screwed 
into  the  cylinder  and  the  spark  plug  is  fitted  to  its  upper  portion. 
When  it  is  desired  to  relieve  the  compression,  the  valve  portion  is 
turned  in  such  a  way  that  a  passage  is  provided  from  the  interior 
of  the  fitting  to  the  outer  air.  At  the  same  time  when  the  valve  is  in 
the  position  shown  in  illustration,  gasoline  may  be  introduced  into 
the  cylinder  for  priming  purposes.  It  is  advanced  that  this  method 
of  constructon  also  provides  a  simple  means  of  freeing  the  plug 
points  from  oil  or  particles  of  carbon  if  the  cock  is  opened  while  the 
engine  is  running.  The  high  pressure  gas  which  brushes  by  the 
points  on  its  way  out  of  the  cylinder  tends  to  dislodge  any  particle  of 
foreign  matter  which  may  be  present  near  the  spark  gap.  The  same 
objections  apply  to  this  method  of  mounting  as  to  that  illustrated 
at  A. 

Spark  plugs  are  made  in  many  different  forms  and  some  have 
been  designed  with,  a  view  of  permitting  one  to  see  if  the  charge  is 
being  .exploded  regularly  in  the  cylinder  by  some  form  of  transparent 
material  for  insulation,  so  that  the  light  produced  by  the  explosion 
could  be  seen  from  the  outside  of  the  cylinder.  The  simplest  method 
of  determining  if  a  spark  is  occurring  regularly  between  the  points 
is  to  use  some  form  of  spark  gap  which  is  interposed  between  the 
source  of  current  and  the  plug  terminal.  A  device  of  this  nature  is 


The  Modern  Gasoline  Automobile 


337 


shown  at  Fig.  185,  A.  It  consists  of  a  body  of  insulating  material 
which  carries  in  a  glass  tube  two  points,  which  are  separated  by  a 
slight  air  space.  The  eye  or  hook  end  is  attached  to  the  plug  ter- 
minal, while  the  other  end  is  attached  to  the  secondary  wire.  If  the 
current  is  passing  between  the  points  of  the  plug,  a  spark  will  take 


Terminal  for 
-High  Tension  Wire 


^Terminal 
for  Plug 


Spark  Points 


Fig.  185. — Novel  Spark  Plugs  and  Accessory  Parts.  A — Spark  Gap  Designed 
to  be  Placed  in  Series  with  Plug  Electrode  and  Current  Source.  B — Plug 
Shell  with  Glass  Insets  to  Show  Spark.  C — Spark  Plug  with  Waterproof 
Terminal  Cover. 

place  between  the  points  of  the  auxiliary  spark  gap  every  time  one 
occurs  between  the  points  of  the  plug  in  the  cylinder. 

It  is  claimed  that  there  are  certain  advantages  obtained  when  a 
spark  gap  is  used  in  the  circuit,  in  that  the  spark  in  the  cylinder  is 
more  effective  and  less  liable  to  be  short  circuited  by  particles  of 
foreign  matter.  At  the  other  hand,  others  contend  that  the.  current 
must  be  stronger  to  jump  two  gaps  than  would  be  required  if  only 


338  The  Modern  Gasoline  Automobile 

the  resistance  of  one  was  to  be  overcome.  While  very  popular  at  one 
time,  the  spark  gap  is  of  rather  doubtful  utility  and  is  seldom  used 
at  the  present  time,  except  as  a  means  of  indicating  if  spark  has 
taken  place  between  the  points  of  the  spark  plug.  It  is  apt  to  be 
somewhat  misleading,  however,  because  even  if  the  points  of  the  plug 
are  short  circuited  and  no  spark  is  taking  place  between  the  plug 
points,  and  yet  current  is  passing  to  the  ground,  a  spark  will  con- 
tinue to  take  place  at  the  auxiliary  spark  gap.  The  device  is  use- 
ful in  showing  when  there  is  a  break  or  derangement  of  the  wiring 
or  coils. 

A  form  of  spark  plug  having  glass  bull  eyes  set  into  the  plug  shell 
or  body  is  shown  at  Fig.  185,  B.  These  simple  lenses  are  made  of 
specially  compounded  glass,  which  has  a  high  resistance  to  heat  and 
every  time  an  explosion  takes  place  in  the  cylinder  the  light  resulting 
causes  a  flash  which  is  readily  seen  through  the  lens.  If  the  flashing 
is  regular  it  is  safe  to  assume  that  the  cylinder  is  functioning  prop- 
erly, but  should  the  flashes  be  intermittent  or  separated  by  unequal 
intervals  of  time  the  cylinder  is  missing  explosions. 

It  is  often  desirable  to  have  a  water-tight  joint  between  the  high 
tension  cable  and  the  terminal  screw  on  top  of  the  insulating  bush- 
ing of  the  spark  plug,  especially  in  marine  applications.  The  plug 
shown  at  C  is  provided  with  an  insulating  member  or  hood  of  porce- 
lain, which  is  secured  by  a  clip  in  such  a  manner  that  it  makes  a 
water-tight  connection.  Should  the  porcelain  of  a  conventional  form 
of  plug  become  covered  with  water  or  dirty  oil,  the  high-tension  cur- 
rent is  apt  to  run  down  this  conducting  material  on  the  porcelain  and 
reach  the  ground  without  having  to  complete  its  circuit  by  jumping 
the  air  gap  and  producing  a  spark.  It  will  be  evident  that  wherever 
a  plug  is  exposed  to  the  elements,  which  is  often  the  case  in  motor- 
cycle or  motor-boat  service,  that  it  should  be  protected  by  an  insulat- 
ing hood  which  will  keep  the  insulator  dry  and  prevent  short  circuit- 
ing of  the  spark. 

Plugs  for  Two-Spark  Ignition. — On  some  forms  of  engines,  es- 
pecially those  having  large  cylinders,  it  is  sometimes  difficult  to  secure 
complete  combustion  by  using  a  single-spark  plug.  If  the  combustion 
is  not  rapid  the  efficiency  of  the  engine  will  be  reduced  proportionate- 
ly. The  compressed  charge  in  the  cylinder  does  not  ignite  all  at 


The  Modern  Gasoline  Automobile  339 

once  or  instantaneously,  as  many  assume,  but  it  is  the  strata  of  gas 
nearest  the  plug  which  is  ignited  first.  This  in  turn  sets  fire  to  con- 
secutive layers  of  the  charge  until  the  entire  mass  is  aflame.  One 
may  compare  the  combustion  of  gas  in  the  gas-engine  cylinder  to  the 
phenomena  which  obtains  when  a  heavy  object  is  thrown  into  a  pool 
of  still  water.  First  a  small  circle  is  seen  at  the  point  where  the 
object  has  passed  into  the  water,  this  circle  in  turn  inducing  other 
and  larger  circles  until  the  whole  surface  of  the  pool  has  been 
agitated  from  the  one  central  point.  The  method  of  igniting  the 
gas  is  very  similar  as  the  spark  ignites  the  circle  of  gas  immediately 
adjacent  to  the  sparking  point,  and  this  circle  in  turn  ignites  a 
little  larger  one  concentric  with  it.  The  second  circle  of  flame  sets 
fire  to  more  of  the  gas,  and  finally  the  entire  contents  of  the  combus- 
tion chamber  are  burning. 

While  ordinarily  combustion  is  sufficiently  rapid  with  a  single  plug 
so  that  the  proper  explosion  is  obtained  at  moderate  engine,  speed?, 
if  the  engine  is  working  fast  and  the  cylinders  are  of  large  capacity, 
more  power  may  be  obtained  by  setting  fire  to  the  mixture  at  two 
different  points  instead  of  but  one.  This  may  be  accomplished  by 
using  two  sparking  plugs  in  the  cylinder  instead  of  one,  and  experi- 
ments have  shown  that  it  is  possible  to  ^ain  from  twenty-five  to  thirty 
per  cent  in  motor  power  at  high  speed  with  two-spark  plugs,  because 
the  combustion  of  the  gas  is  accelerated  by  igniting  the  gas  simul- 
taneously in  two  places.  To  fit  a  double-spark  system  successfully, 
one  of  the  plugs  must  be  a  double  pole  member  to  which  the  high- 
tension  current  is  first  delivered,  while  the  other  may  be  one  of 
ordinary  construction. 

A  typical  double-pole  plug  is  shown  in  section  at  Fig.  186,  A.  In 
this  member  two  concentric  electrodes  are  used,  these  being  well  in- 
sulated from  each  other.  One  of  these  is  composed  of  the  usual  form 
passing  through  the  center  of  the  insulating  bushing,  while  the  other  is 
a  metal  tube  surrounding  the  tube  of  insulating  material  which  is 
wound  around  the  center  wire.  The  current  enters  the  plug  through 
the  terminal  at  the  top  in  the  usual  manner,  but  it  does  not  go  to 
the  ground  because  the  sparking  points  are  insulated  from  the  steel 
body  of  the  plug  which  screws  into  the  cylinder.  After  the  current 
has  jumped  the  gap  between  the  sparking  head  and  the  point,  it 


340 


The  Modern  Gasoline  Automobile 


flows  back  to  the  terminal  plate  at  the  top,  from  which  it  is  conducted 
to  the  insulated  terminal  of  the  usual  type  plug. 

The  method  of  wiring  these  plugs  is  shown  at  Fig.  186,  B.     The 
secondary  wire  from  the  coil  or  magneto  is  attached  to  the  central 


Mica 
Washers 


Fig.  186.— Double-Pole  Spark  Plug  and  Method  of  Applying  It  to  Obtain  Two 
Sparks  in  the  Cylinder. 

terminal  of  the  double-pole  plug,  and  another  cable  is  attached  to 
the  insulated  terminal  plate  below  it  and  to  the  terminal  of  the  regu- 
lar type  plug.  One  is  installed  over  the  inlet  valve,  the  other  over 
the  exhaust  valve,  if  the  system  is  fitted  to  a  T  head  cylinder.  Before 
the  current  can  return  to  the  source  it  must  jump  the  gap  between 
the  points  of  the  double-pole  plug  as  well  as  those  of  the  ordinary 
plug,  which  is  grounded  because  it  is  screwed  into  the  cylinder. 
When  a  magneto  of  the  high-tension  type  furnishes  the  current  a 


The  Modern  Gasoline  Automobile 


341 


double  distributor  is  sometimes  fitted,  which  will  permit  one  to  use 
two  ordinary  single-pole  plugs  instead  of  the  unconventional  double- 
pole  member.  Each  of  the  plugs  is  joined  to  an  individual  distrib- 
utor, and  as  but  one  primary  contact  breaker  or  timer  is  used  to 
determine  the  time  of  sparking  at  both  plugs,  the  ignition  is  properly 
synchronized  and  the  sparks  occur  simultaneously. 

Typical  Battery  Ignition  Systems. — The  components  of  typical  bat- 
tery ignition  systems  may  be  easily  determined  by  studying  the  illus- 
trations given  at  Figs.  187,  188,  and  189.  The  four-cylinder  ignition 
group  shown  at  Fig.  187  depicts  the  conventional  method  of  wiring 


High  Tension  Wires 


Primary  Circuit 


Dry  Coils 


^Storage  Battery 


Fig.  187.— Assembly  View  of  Four-Cylinder  Ignition  Group  Showing  All  Devices 
and  Methods  of  Wiring. 

two  sets  of  batteries,  a  four-point  timer  or  commutator,  and  a  four- 
unit  induction  coil  together.  It  will  be  seen  that  eight  dry  cells  are 
wired  together  in  series  and  are  used  as  an  auxiliary  to  a  six-volt  or 
three-cell  storage  battery.  The  negative  terminals  of  the  storage  bat- 
tery and  dry  cell  set  are  coupled  together  by  a  short  length  of  wire 


342 


The  Mo'dern  Gasoline  Automobile 


and  are  grounded  by  being  attached  to  the  engine  base  by  a 
suitable  conductor.  The  positive  terminals  are  coupled  to  the 
two  binding  posts  under  the  switch  or  the  coil.  The  four  points  of 
the  commutator  are  attached  to  the  different  units  of  the  coil  while 
the  secondary  wires  run  from  the  high-tension  terminals  on  the 
bottom  of  the  coil  to  the  spark  plugs  in  the  cylinders.  If  the  switch 
lever  is  placed  on  one  contact  button,,  the  current  is  obtained  from  the 
dry  cells.  If  it  is  swung  over  to  the  other  side,  electricity  from  the 
storage  battery  is  utilized. 


Plug 


Fig.  188.— Methods  of  Employing  Single  Coil  to  Fire  Four  Cylinders  when  Sec- 
ondary Current  is  Distributed  Instead  of  Battery  Energy. 

A  typical  high-tension  distributor  system  is  shown  at  Fig.  188. 
Two  sources  of  primary  current  are  provided,  one  being  a  six-cell,  dry 
battery,  the  other  a  three-cell,  or  six-volt  storage  battery.  The  bat- 
tery connections  are  similar  to  those  previously  shown  and  but  a 
single  unit  coil  is  needed  to  fire  all  cylinders.  A  single  primary  wire 
is  attached  to  the  commutator  section  of  the  distributor.  The  second- 


The  Modern  Gasoline  Automobile 


343 


ary  wire  from  the  induction  coil  is  joined  to  the  distributing  terminal 
on  the  top  of  the  distributor,,  from  which  it  is  delivered  to  the  collect- 
ing terminals  spaced  on  quarters  around  the  outer  periphery  of  the 
distributor  casing  by  means  of  a  central  distributing  segment.  Suit- 
able conductors  connect  the  distributor  with  the  spark  plugs  in  the 
cylinders. 


Side  View 


Firing  Order  1,2,3,6,5,4- 


Spark  Plug 


^Ground 


^Cylinder  Pair- 


Fig.  189. — Distributor  and  Coil  Ignition  Group  for  Six-Cylinder  Motor  Showing 
Order  of  Firing  and  Wiring  Connections  Clearly. 

The  illustration  at  Fig.  189  is  practically  the  same  as  that  at 
Fig.  188,,  except  that  a  distributor  capable  of  firing  a  six-cylinder 
engine  is  used.  If  individual  unit  coils  were  to  be  employed,  as  is 
the  case  at  Fig.  187,,  the  coil  box  would  contain  six  units  and  the 
primary  timer  would  have  six  contact  points.  The  wiring  would  be 
considerably  more  complicated  than  the  system  outlined.^ 

Features  of  Low-Tension  Ignition  System. — Though  the  low-tension 
ignition  system  is  seldom  used  at  the  present  time,  a  brief  descrip- 
tion of  the  method  of  producing  a  make-and-break  spark  is  desirable 
so  the  reader  may  gain  a  thorough  knowledge  of  the  methods  of 
ignition  the  vogue.  In  order  to  obtain  a  spark  in  the  cylinder  of  any 


344 


The  Modern  Gasoline  Automobile 


engine,  it  is  necessary  that  there  be  a  break  in  the  circuit  and  that 
this  break  or  interruption  be  inside  of  the  combustion  chamber.  The 
igniter  plate  used  is  different  in  construction  from  the  spark  plug 
forming  part  of  the  high-tension  system,  as  the  break  is  made  by 
moving  contacts  which  serve  to  time  the  spark  as  well  as  produce  it. 


Plate 


Rocker  Arm 


B 


^Anvil  Insulator 


Fig.  190. — Low-Tension  Ignition  Plate  by  which  Spark  is  Produced  in  Some 
Locomobile  Engine  Cylinders.  A — External  View  Showing  Rocker  Arm. 
B — Interior  View  Depicting  Contact  Points.  C — Method  of  Operation. 

A  typical  igniter  is  shown  at  A  and  B,  Fig.  190.  It  consists  of  a 
drop-forged  plate  approximately  triangular  in  form  which  has  a  coni- 
cal ground  surface  to  fit  a  corresponding  female  member  in  the  com- 
bustion chamber.  It  is  secured  by  three  bolts  to  a  corner  of  the 


The  Modern  Gasoline  Automobile  345 

cylinder  close  to  the  inlet  valve  so  the  contact  points  will  be  traversed 
by  the  gases  entering  from  the  carburetor.  As  shown  at  B,  the  fixed 
contact  point  is  called  the  anvil,  while  the  movable  or  rocking  mem- 
ber is  called  the  hammer.  The  anvil  is  insulated  from  the  igniter 
plate  by  a  bushing  of  mica  or  lava,  and  the  hammer  alternately  makes 
and  breaks  contact  with  the  anvil.  The  method  of  actuating  the  ham- 
mer by  a  rocker  arm  is  clearly  shown  at  C.  The  rocker  arm  5  is  in 
the  form  of  a  short  lever  ending  in  a  slotted  opening  which  is  con- 
nected to  the  top  of  the  vertical  lifter  rod  9.  This  is  actuated  by  a 
cam  on  the  inlet  valve  cam  shaft  which  raises  the  valve  plunger  11  in 
the  guide  bushing  10.  When  the  lifter  rod  moves  upward  the  con- 
tact point  on  the  hammer  inside  of  the  cylinder  comes  into  contact 
with  the  platinum  point  on  the  anvil  and  closes  the  circuit.  When 
the  igniter  cam  reaches  the  proper  point  for  igniting  the  charge  the 
lifter  rod  9  falls  and  as  the  action  is  quickened  by  a  spring  at  the 
bottom  of  the  lifter  rod  the  hammer  arm  4  is  separated  from  the  con- 
tact point  on  the  anvil  6  and  a  spark  takes  place  as  the  points  are 
pulled  apart. 

The  coil  used  when  batteries  are  employed  to  furnish  the  current 
is  a  simple  form.  It  is  a  winding  of  comparatively  coarse  wire 
around  a  core  composed  of  a  bundle  of  soft  iron  wire.  The  battery 
current  is  intensified  to  a  certain  extent  by  the  self-induction  of  one 
layer  of  wire  upon  the  others,  and  when  contact  is  broken  a  brilliant 
spark  occurs  between  the  points  of  the  igniter  plate.  Batteries  are  sel- 
dom used  for  regular  service  on  the  low-tension  system  because  the 
demands  are  too  severe. 

One  of  the  advantages  of  this  system  is  that  the  wiring  is  ex- 
tremely simple,  as  will  be  seen  by  consulting  the  diagram  of  the  low- 
tension  ignition  system  illustrated  at  Fig.  191.  In  this  both  a  low- 
tension  magneto  and  set  of  batteries  are  provided,  the  former  being 
used  for  regular  ignition  while  the  latter  are  carried  for  emergency 
service.  A  simple  form  of  magneto  will  serve  any  number  of  cyl- 
inders because  the  insulated  terminals  of  the  igniters  are  joined  to- 
•gether  by  a  simple  conductor  or  bus  bar.  A  wire  from  the  magneto 
terminal  is  joined  to  one  side  of  the  switch,  while  the  other  side  of 
the  switch  is  coupled  to  the  coil  which  is  carried  in  the  battery  box. 
A  short  wire  connects  the  top  of  the  switch  lever  with  the  bus  bar. 


346 


The  Modern  Gasoline  Automobile 


If  the  switch  lever  is  swung  to  the  left,  the  magneto  produces  the 
current  for  the  igniters,  and  if  the  switch  lever  is  placed  on  the  button 
at  the  right,  the  current  supply  is  taken  from  the  batteries.  The  dry 


Switch 


Battery 


Magneto 


Battery 


Fig.  191. — Low-Tension  Ignition  System  for  Four-Cylinder  Motor  Utilizes  Bat- 
tery and  Magneto  for  Current  Production.  Note  Simple  Wiring — All  Con- 
ductors Conveying  Low-Tension  Current. 

cells  are  joined  together  in  series  connection,  one  pole  being  joined 
to  a  coil  terminal,  the  other  being  grounded.  The  coil  and  the  igniter 
plates  are  in  series  with  the  batteries  and  the  current  is  returned  to 
the  ground  through  the  rocker  arm,  which  is  a  metallic  contact  with 
the  igniter  plate. 

The  disadvantage  which  has  militated  against  the  general  use  of 
the  make-and-break  system  of  ignition  is  that  it  is  very  difficult  to 
obtain  synchronized  spark  after  the  mechanism  had  become  worn,  and 
unless  the  igniter  plates  were  kept  in  perfect  adjustment  the  spark 
time  would  vary  and  the  efficiency  of  the  engine  would  be  lowered. 
As  the  moving  electrodes  operate  under  extremely  disadvantageous 
conditions  "it  is  difficult  to  prevent  rapid  wear  of  the  rocker  arm 
bearing  at  the  igniter  plate  and  consequent  leakage  of  gas  results. 


The  Modern  Gasoline  Automobile 


347 


Owing  to  the  multiplicity  of  joints  in  the  operating  mechanism  it  is 
difficult  to  secure  regular  action  without  backlash  or  lost  motion. 

With  a  high-tension  system  there  are  no  moving  parts  inside  of 
the  cylinder  and  it  is  not  difficult  to  maintain  a  tight  joint  between 
the  plug  body  and  the  cylinder  head.  The  timer  mechanism  which 
is  employed  when  batteries  and  coils  are  utilized  to  furnish  the  cur- 
rent is  a  comparatively  simple  device  which  is  not  liable  to  wear  be- 
cause it  can  be  easily  oiled  and  has  a  regular  rotating  movement  which 
can  operate  without  getting  out  of  time  much  better  than  the  recipro- 
cating parts  of  the  make-and-break  mechanism.  When  a  direct  high- 
tension  magneto  is  used  the  system  is  not  much  more  complicated  as 
far  as  wiring  is  concerned  than  a  low-tension  group,  and  as  the 
ignition  is  more  reliable  it  is  not  strange  that  jump  spark  or  high- 
tension  ignition  is  almost  generally  used  in  automobile  practice. 


Long  Platinum 
Tipped 
Screw 


Carbon  Holder 


Collector 
Ring 


\Brass  Plate 
^Condenser  Timjng 
Case 


Fig.  192. — Simple  High-Tension  Magneto  for  One-Cylinder  Ignition.     A  Com- 
plete Apparatus  Comprising  Source  of  Current  and  Timing  Device  as  WeH. 

Magneto  Generator  Construction. — The  magneto  is  a  simple  form 
of  dynamo  and  a  mechanical  generator  of  electricity  in  which  per- 
manent magnets  are  used  to  produce  the  magnetic  field  and  between, 
which  the  armature  revolves.  The  permanent  magnets  are  called 
"  field  magnets  "  and  at  their  ends  are  provided  cast-iron  shoes  which 


348  The  Modern  Gasoline  Automobile 

form  the  walls  of  the  armature  tunnel  and  which  are  known  as  pole 
pieces.  A  typical  magneto  adapted  for  single-cylinder  ignition  is 
shown  in  section  at  Fig.  192.  It  consists  of  two  compound  horse- 
shoe magnets  attached  to  the  pole  pieces  which  collect  and  concentrate 
the  magnetism  upon  the  armature.  The  armature  is  shuttle-shaped 
and  carries  a  double  winding  of  wire  which  consists  of  two  coils,  one 
of  coarse,  the  other  of  fine  conductor.  The  armature  is  attached  to 
end  pieces  which  carry  shafts  and  the  whole  assembly  revolves  on 
annular  ball  bearings.  An  ebonite  or  hard  rubber  spool  is  carried 
at  one  end  while  the  condenser  is  housed  at  the  other.  The  make- 
and-break  mechanism  is  partly  carried  by  an  oscillating  casing  and 
the  revolving  member  is  turned  from  the  armature  shaft. 

The  current  generated  in  the  coil  is  delivered  to  a  metal  ring  on 
the  ebonite  spool  from  which  it  is  taken  by  a  carbon  brush  and  de- 
livered directly  to  the  spark  plug.  Every  time  the  contact  points 
in  the  make-and-break  devices  become  separated,  a  current  of  high 
potential  passes  through  the  wire  attached  to  the  spark  plug  and 
produces  a  spark  between  the  points.  The  magneto  is  the  simplest 
and  most  practical  form  of  ignition  appliance  as  it  is  self-contained 
and  includes  the  current  generator  and  the  timing  device  in  one  unit. 
In  the  one-cylinder  form  shown  all  connections  are  made  inside  of 
the  device  and  but  one  wire  leading  to  the  spark  plug  is  necessary  to 
form  the  external  circuit. 

A  magneto  employed  for  multiple-cylinder  ignition  is  not  much 
more  complicated  than  that  used  for  single-cylinder  service,  the  only 
difference  being  that  a  different  form  of  cam  is  provided  in  the 
breaker  box  and  that  a  secondary  distributor  is  added  to  commutate 
the  current  to  the  plugs  in  the  various  cylinders.  The  distributor 
consists  of  a  block  of  insulating  material  fixed  to  the  magnets  which 
carries  as  many  segments  as  there  are  cylinders  to  be  fired.  .A  cen- 
tral distributing  arm  or  segment  is  driven  from  the  armature  shaft  by 
means  of  gearing,  and  is  employed  to  distribute  the  high-tension 
current  to  the  spark  plugs.  The  spacing  of  the  distributor  segments 
does  not  differ  materially  from  that  of  the  battery  timers  previously 
described. 

Various  distributor  forms  used  on  magnetos  are  shown  at  Fig. 
193.  That  at  A  is  employed  for  a  double  opposed  cylinder  motor  and 


The  Modern  Gasoline  Automobile 


349 


the  contacts  are  separated  by  a  space  of  180  degrees.  When  a  three- 
cylinder  engine  is  used,  as  is  sometimes  the  case  in  the  two-cycle  forms, 
the  distributor  segments  are  separated  by  distances  of  120  degrees. 


f    i 


D 


Fig.  193. — How  Distributor  Contacts  are  Spaced  on  Two-,  Three-,  Four-  and  Six- 
Cylinder  Magnetos. 

If  the  distributor  is  used  on  a  four-cylinder  motor  the  segments  are 
spaced  90  degrees  apart,  as  shown  at  C.  To  fire  a  six-cylinder  motor, 
six  segments  must  be  used  and  they  are  placed  60  degrees  apart,  as 
indicated  at  D. 

The  speed  at  which  the  armature  of  the  magneto  turns  also  varies 
with  the  number  of  cylinders.  One-  and  two-cylinder  forms  turn  at 
cam-shaft  speed.  The  three-cylinder  types  when  applied  to  a  four- 
cycle engine,  turn  #t  three  quarters  the  crank-shaft  speed.  The  four- 


350  The  Modern  Gasoline  Automobile 

cylinder  magneto  armature  is  driven. at  crank-shaft  speed,  while  that 
of  the  six-cylinder  forms  turn  at  one  and  one  half  times  crank-shaft 
speed.  When  used  on  two-cycle  motors,  the  speeds  given  for  four- 
cycle engines  of  the  same  number  of  cylinders  should  be  doubled. 

The  important  parts  of  a  four-cylinder  form  of  high-tension  mag- 
neto are  shown  at  Fig.  194,  which  is  a  view  of  a  partially  dismantled 
device.  The  armature  assembly  and  one  of  the  end  plates  by  which 
it  is  supported  are  shown  at  the  extreme  left.  Attached  to  the  end  of 
the  armature  shaft  are  the  distributor  drive  pinion  and  the  ebonite 
spool  which  carries  the  collector  ring.  The  timer  case  and  interrupter 
assembly  are  shown  at  the  extreme  right.  Above  it  the  distributor 
case  is  clearly  depicted.  When  the  device  is  assembled  the  end  of  the 
armature  shaft  protrudes  through  the  housing  at  the  lower  part  of  the 
magnet  assembly  which  is  shown  in  the  center  of  the  group,  with 
the  end  plate  which  carries  the  distributor  gear  and  disk  and  one 
end  of  the  armature  in  place.  The  distributor  gear  serves  to  drive 
a  hard  rubber  plate  in  which  the  distributor  segment  is  imbedded. 
When  the  distributor  case  is  screwed  in  place,  the  carbon  brushes, 
which  are  spaced  around  the  interior  of  the  distributor  case,  collect 
current  from  the  revolving  distributor  segment  and  lead  it  to  the 
spark  plugs  by  suitable  cables  which  run  from  the  terminals  at  the 
top  of  the  distributor  casing. 

Two  systems  of  high-tension  magneto  ignition  are  used,  one 
termed  the  true  high-tension  system,  in  which  a  current  of  high  po- 
tential is  delivered  directly  from  the  armature ;  the  other  is  the  trans- 
former coil  system,  so  termed  because  the  current  produced  by  the 
armature  winding  is  of  low  tension  and  must  be  stepped  up  or  in- 
creased in  value  before  it  is  delivered  to  the  spark  plug  by  an  induc- 
tion coil  similar  in  construction  to  that  needed  in  battery-ignition 
systems.  In  the  former  apparatus  the  high-tension  current  is  pro- 
duced by  means  of  a  secondary  winding  on  the  armature  itself,  and  as 
the  whole  apparatus  is  self-contained  it  is  much  more  compact  and 
simpler  to  install  than  those  which  need  a  separate  transformer  coil. 

The  simplified  wiring  system  of  a  true  high-tension  magneto  is 
shown  at  Fig.  195.  The  armature  carries  two  windings,  one  indicated 
by  the  heavier  lines  at  the  bottom  called  the  "  primary  " ;  the  other, 
composed  of  finer  conductor,  is  known  as  the  "  secondary."  One  end 


352 


The  Modern  Gasoline  Automobile 


of  the  primary  winding  is  grounded,  the  other  is  joined  to  the  fixed 
contact  screw  of  the  contact  breaker.  This  end  is  also  joined  to  one 
end  of  the  secondary  winding  and  the  free  end  of  the  secondary  wind- 
ing is  attached  to  the  collector  ring  carried  by  the  ebonite  spool. 
When  the  contact  points  separate,  a  current  is  induced  in  the  primary 


L 


g=J £=f -Jgg  Primary  Winding 


Secondary  Winding 

Frame 


^Safety  Spark  Gap 
Secondary 


:  Contact  Breaker 


Primary/ 


Fig.  195. — Simple  Wiring  Scheme  when  Four-Cylinder  Magneto  is  Utilized  for 
Gas-Engine  Ignition.  Magneto  Members  Shown  Separate  to  Facilitate 
Explanation  of  Principles  of  Operation. 

and  secondary  windings  and  is  delivered  to  the  center  terminal  of 
the  distributor  disk  by  the  carbon  brush  which  bears  against  the  col- 
lector ring. 

The  various  segments  of  the  distributor  are  connected  to  the 
spark  plugs  in  the  cylinders,  and  every  time  the  contact  points  sep- 
arate a  spark  will  be  produced  at  one  of  the  plugs  because  the  revolv- 
ing distributor  brush  will  be  in  contact  with  one  of  the  distributor 
segments.  A  cross-section  view  of  the  Bosch  high-tension  magneto 
is  shown  at  Fig.  196  and  the  important  parts  are  clearly  shown.  As 
the  internal  connections  are  very  similar  to  those  shown  diagrammati- 
cally  at  Fig.  195,  the  same  description  given  of  the  course  of  current 
in  the  former  applies  equally  well  to  the  latter. 


353 


354 


The  Modern  Gasoline  Automobile 


The  wiring  of  a  four-cylinder  magneto  which  employs  a  trans- 
former coil  is  shown  at  Fig.  197.  A  set  of  batteries  is  provided  to 
furnish  current  for  starting,  as  it  is  sometimes  difficult  to  turn  the 
motor  sufficiently  fast  by  hand  to  generate  the  proper  amount  of 
magneto  current  to  insure  prompt  starting.  The  high-tension  wire 


Trans fo  rmerCoilr- 


High  Tension  Wire  to  Plug 


Distributor  Housing 


Wire  To 
Stationary  Winding 


Wire 

Bed  Wire 
—Green  Wire 
Contact  Breaker  Housing 


Dry  Battery 


Fig.  197. — Wiring  Diagram  Outlining  Method  of  Combining  Magneto  and  Trans- 
former Coil  to  Form  Device  for  Four-Cylinder  Ignition.  «  . 

from  the  spark  coil  or  transformer  is  led  to  the  center  of  the  distribu- 
tor and  the  current  is  commutated  to  the  plugs  just  as  though  the 
high-tension  current  had  been  produced  in  the  magneto  itself  instead 
of  in  the,  transformer. 

The  Connecticut  magneto,  which  is  a  transformer  coil  type,  is 
shown  in  longitudinal  section  and  end  elevation  at  Fig.  198.     In  this, 


355 


356 


The  Modern  Gasoline  Automobile 


the  transformer  coil  is  mounted  between  the  magnets  above  the  arma- 
ture tunnel  and  the  secondary  current  is  applied  directly  to  the  dis- 
tributing brush  by  means  of  a  secondary  collecting  member  which 
bears  against  a  suitable  terminal  in  the  bottom  of  the  coil  casing. 
With  this  magneto  the  wiring  is  as  simple  as  it  would  be  with  the 
true  high-tension  form  and  only  five  wires  are  needed  in  the  external 


Secondary  Winding 

Primary  Winding 

Stationary  Windin 


Cam 


Fig.  199. — Showing  Application  of  High-Tension  Principle  in  K.W.  Four-Cylinder 

Magneto. 

circuit.  Of  these,  four  secondary  leads  run  direct  from  the  distribu- 
tor to  the  plug  while  the  remaining  one  is  a  primary  ground  wire 
having  a  switch  in  circuit  through  which  the  primary  coil  current 
may  be  grounded  instead  of  going  to  the  transformer  coil,  thus  stop- 
ping the  motor. 

All  magnetos  do  not  employ  a  revolving  winding.  Some  utilize 
a  stationary  coil  of  wire  and  use  rotating  inductor  members  to  cause 
the  lines  of  magnetic  force  to  flow  through  the  wire  and  generate  a 


357 


358  The  Modern  Gasoline  Automobile 

current  therein.  A  simplified  wiring  diagram  of  the  K.W.  magneto, 
which  is  an  igniter  of  this  type,  is  shown  at  Fig.  199,  while  a  sectional 
view  of  the  device  itself  is  presented  at  Fig.  200.  The  stationary  coil  is 
composed  of  two  windings,  a  primary  and  a  secondary,  and  is 
mounted  in  the  center  of  the  device  so  that  the  rotary  inductor  shaft 
passes  through  it,  one  inductor  being  placed  at  each  side  of  the  station- 
ary coil.  The  secondary  wire  passes  through  the  insulated  electrode 
through  a  bridge  or  strap  member  which  is  connected  at  one  end  to 
the  spark  gap  and  at  the  other  to  a  bent  conductor  which  conveys  the 
current  to  a  revolving  distributor  arm. 

When  the  contact  points  are  separated  by  the  cam  a  current  of 
electricity  is  induced  in  the  primary  coil  and  transformed  to  a  high- 
tension  current  in  the  secondary  winding  and  is  delivered  to  the  spark 
plugs  by  the  conventional  form  of  distributor.  Except  for  the  sta- 
tionary winding  and  the  use  of  inductor  pieces  to  reverse  the  lines 
of  magnetism  through  the  coil,  the  construction  does  not  differ  from 
the  forms  previously  described.  It  is  advanced  that  the  stationary 
winding  offers  some  advantages  inasmuch  as  brushes  are  not  required 
to  collect  the  primary  current. 

The  function  of  the  safety  spark  gap  is  to  take  care  of  any  excess 
current  which  might  damage  the  insulation  of  the  winding  by  allow- 
ing it  to  go  to  the  ground.  The  air  gap  between  the  points  has  high 
enough  resistance  so  that  the  spark  will  not  jump  it  under  normal 
conditions,  but  should  the  voltage  become  suddenly  increased  in  value, 
as  might  be  the  case  if  one  of  the  plug  wires  became  disconnected, 
it  will  leap  this  gap  in  preference  to  overcoming  the  resistance  of  the 
insulation  of  the  winding.  The  purpose  of  the  condenser  in  a  mag- 
neto is  the  same  as  that  used  in  a  coil,  i.  e.,  it  is  interposed  in  the 
primary  circuit  in  such  a  way  that  it  is  in  shunt  connection  with  the 
contact-breaker  points  and  absorbs  any  current  which  would  tend 
to  produce  excessive  sparking. 

Application  of  Typical  Magneto  Forms. — Some  of  the  leading 
forms  of  American  magnetos  are  shown  at  Fig.  201.  That  at  A  is 
the  Heinze  device  and  differs  from  the  conventional  form  in  that 
magnets  of  round  section  are  used  instead  of  the  conventional  horse- 
shoe magnets  of  rectangular  cross  section.  The  form  shown  at  B  is 
the  Kingston  magneto,  which  is  used  in  connection  with  a  transformer 


The  Modern  Gasoline  Automobile 


359 


coil.  The  Connecticut,,  which  has  been  previously  shown  in  section 
at  Fig.  198,  is  depicted  at  C.  The  double  distributor  form  intended 
to  be  used  in  connection  with  two-spark  ignition  systems  shown  at  D 
is  a  Splitdorf  design  and  should  be  used  with  a  separate  transformer 
coil. 


Fig.  201. — Typical  American  Magneto  Forms.  A — Heinze  Machine  with  Round 
Section  Field  Magnets.  B — Kingston  Magneto  for  Dual  Ignition.  C — 
Clean-Cut  Design  of  Connecticut  Device.  D — Splitdorf  Double  Distributor 
Form  Designed  for  Two-Spark  Ignition  Systems. 

The  usual  method  of  installing  a  magneto  is  to  place  it  on  a 
bracket  fastened  to  the  engine  base  so  the  contact  breaker  and  dis- 
tributor will  be  handy  for  immediate  inspection  or  adjustment.  It 


360 


The  Modern  Gasoline  Automobile 


is  desirable  to  place  the  device  on  the  inlet  side  of  the  engine  and  as 
far  away  from  the  exhaust  piping  as  possible  because  the  excess  heat 
which  exists  at  this  point  is  liable  to  injure  the  insulation  of  the  wind- 
ings. Methods  of  installation  which  are  typical  of  conventional  prac- 
tice are  shown  at  Fig.  202.  At  A  the  magneto  is  placed  on  a  cast 


Timing  Gear  Case 


Nut 


Fig.  202. — Conventional  Methods  of  Placing  and  Driving  Magneto  Generators. 
A — System  Used  on  Regal  Engine.  B — Magneto  is  Driven  from  Pump- 
Shaft  Extension  on  Velie  Motors. 

bracket  formed  integral  with  the  top  half  of  the  engine  base  and  is 
driven  from  the  timing  case  at  the  front  of  the  engine  by  a  length 
of  shaft.  At  B  the  magneto  is  also  housed  at  the  rear  end  and  is 
carried  on  a  base  plate  formed  integrally  with  one  of  the  crank-case 


The  Modern  Gasoline  Automobile  361 

supporting  arms.  The  drive  is  by  an  extension  of  the  pump  shaft, 
that  member  being  driven  by  suitable  gearing  in  the  cam-shaft  timing 
gear  casing. 

Gear  drive  is  the  best  method  of  driving  a  magneto  armature  and 
direct  spur-gear  connection  is  better  than  either  bevel  or  spiral  gear 
trains  because  it  is  the  best  wearing  form  of  gearing.  Silent  chains 
may  be  used  for  driving  if  some  form  of  adjustment  is  provided  to 
compensate  for  chain  stretch.  When  a  magneto  is  driven  by  a  shaft, 
as  shown  at  Fig.  202,  A  and  B,  it  is  customary  to  provide  some  sort 
of  a  universal  joint  or  Oldham  coupling  between  the  armature  and 
the  driving  member  in  order  that  any  inaccuracies  in  alignment  of 
the  driving  shaft  will  not  stress  the  ball  bearings  supporting  the 
armature.  It  is  desirable  to  protect  the  instrument  from  oil  or 
water  by  placing  it  in  a  case  of  fiber  or  leather,  and  in  modern  types 
the  contact  breaker  and  distributor  housings  are  closed  by  easily  re- 
moved and  yet  practically  dust-tight  coverings. 

Metallic  or  carbon  particles  and  dirty  oil  may  cause  internal  short 
circuiting  and  it  is  desirable  to  have  the  contact-maker  case  and  the 
distributor  cover  arranged  in  such  a  way  that  they  may  be  easily 
reached  for  cleaning.  Modern  magnetos  are  usually  secured  in  some 
way  that  will  permit  a  ready  removal.  In  that  shown  at  A,  Fig. 
202,  a  number  of  through  bolts  are  screwed  from  the  under  side  of 
the  bracket  into  the  magneto  base  and  it  is  necessary  to  remove  these 
before  the  magneto  can  be  lifted  off  its  support.  The  method 
shown  at  Fig.  202,  B,  is  preferable  as  the  ignition  device  may  be  re- 
moved from  the  base  by  slackening  one  nut  on  the  hinge  bolt  which 
keeps  the  metallic  strap  tight,  thus  holding  the  magneto  in  place. 

Various  other  methods  of  utilizing  strap  members  are  shown  at 
Fig.  203.  In  that  shown  at  A  the  strap  is  made  in  two  pieces  and  is 
held  together  at  the  top  by  a  clamp  bolt.  The  method  of  securing  a 
magneto,  shown  at  B,  is  practically  the  same,  except  that  the  retention 
member  is  a  small  knob  which  can  be  easily  turned  by  the  hand.  At 
C  the  strap  encircles  the  magneto  completely  and  is  held  in  place 
by  a  single  nut  under  the  bracket.  A  modification  of  this  method 
is  depicted  at  D.  The  strap,  in  this  instance,  is  just  bent  over  the 
arch  of  the  magnets  and  held  in  place  by  the  long  swinging  bolt  which 
is  hinged  at  the  bottom  of  the  magneto. 


362 


The  Modern  Gasoline  Automobile 


One  of  the  simplest  methods  of  driving  a  magneto  is  that  shown 
at  Fig.  204,  which  is  a  bottom  view  of  the  Ford  engine  case.  The 
stationary  coils  of  the  magneto  are  attached  to  tke  crank  case,  and  the 


Clamp  Bolt. 


Strap— 


o   o 


r 


Strap 


Fig.  203. — Simple  Methods  of  Holding 'Magnetos  in  Place  on  Engine  Base  to 
Permit  of  Easy  Removal  of  Apparatus  when  Desired. 


The  Modern  Gasoline  Automobile 


363 


revolving  magnets  rotate  with  the  fly  wheel,  which  in  turn  is  securely 
attached  to  the  crank  shaft.  With  this  form  of  drive  there  can  be 
no  interruption  in  current  generation  and  there  are  no  gears,  chains, 
or  other  connections  to  wear  and  produce  noise  or  interfere  with  gen- 
eration of  current. 

When  the  magneto  was  first  introduced  it  was  looked  upon  with 
suspicion  by  the  motoring  public.     Therefore  some  designers  compro- 


Fly wheel 


'Stationary  Coils 


Crankshaft 


Revolving 
Magnets 


Fig.  204. — The  Ford  Magneto  is  Integral  with  Engine  Base,  and  Revolving  Mag- 
nets are  Attached  to  Fly  Wheel.  Thus  Direct  Drive  from  Crank  Shaft  is 
Possible  without  Gearse 

mise  and  furnish  two  separate  systems,  one  composed  of  a  magneto, 
the  other  an  auxiliary  group  comprising  a  battery,  timer  and  coil, 
which  supply  the  current  to  a  set  of  spark  plugs  distinct  from  those 
supplied  from  the  magneto.  It  was  found  difficult  with  some  types 
of  magnetos  to  start  the  engine  directly  from  magneto  current  so 
the  battery  outfit  was  depended  upon  for  starting  the  engine  as  well 
as  emergency  service.  The  parts  of  the  modern  high-tension  mag- 
neto have  been  simplified  and  strengthened  and  as  the  various  parts 
may  be  removed  easily  and  replaced  without  trouble  and  special  care 
taken  so  the  adjustments  and  cleaning  necessary  may  be  easily  under- 
stood by  the  layman  there  is  very  little  liability  at  the  present  time 
of  a  magneto  giving  out  without  warning. 


364 


The  Modern  Gasoline  Automobile 


A  typical  magneto  ignition  system  used  in  connection  with  a 
battery  set  is  shown  at  Fig.  205.  Six  dry  cells  are  used  to  supply  the 
current  and  a  conventional  four-point  timer  commutates  the  battery 


Magneto 


Ground 


Dry  Cell  Battery 


Fig.  205. — Double  Ignition  System  Utilizing  Battery  and  Induction  Coil  Group 
for  Starting  and  Emergency  Service  and  Pittsfield  High-Tension  Magneto 
as  the  Main  Ignition  System. 

current  to  the  four  individual  units  of  the  coil  box5  which  in  turn 
delivers  secondary  current  to  the  plugs.  When  the  switch  is  thrown 
to  one  side  the  magneto  system  is  utilized.  When  the  contacts  are 
reversed  the  battery  system  furnishes  the  ignition  energy.  The  parts 
are  shown  arranged  in  diagram  form  so  that  the  wiring  may  be 
easily  followed  and  the  relation  of  the  various  parts  to  each  other 
definitely  ascertained.  The  methods  of  wiring  typical  double  systems 
are  further  exemplified  by  diagram  shown  at  Fig.  206. 

Connections  of  parts  comprising  the  Bosch  dual  ignition  system 
are  shown  at  Fig.  207.  With  this  method  but  one  set  of  spark 
plugs  is  needed  as  the  secondary  distributor  of  the  magneto  is  utilized 
to  distribute  the  high-tension  current  obtained  either  from  the  mag- 
neto armature  or  the  battery  and  coil  system.  A  separate  timer  is 
used  to  interrupt  the  battery  current,  and  the  coil  carried  on  the  dash 


The  Modern  Gasoline  Automobile 


365 


is  of  such  a  nature  that  depressing  a  button  will  bring  a  vibrator  in 
circuit  and  throw  a  constant  stream  of  sparks  across  the  air  gap  of 
the  spark  plug  in  the  cylinder  about  to  fire.  This  will  start  the  en- 
gine, if  a  four-  or  six-cylinder  form,  without  cranking  when  condi- 
tions are  favorable.  Ordinarily  when  running  on  the  battery  system 


Dry  Cell 
Battery 


Storage 
Battery 


Fig.  206. — Practical  Application  of  Double  Ignition  System  to  Four-Cylinder 

Power  Plant. 


the  coil  vibrator  is  not  used,  a  single  spark  taking  place  between  the 
points  of  the  spark  plug.  The  various  connections  are  clearly  shown 
in  illustration  and  further  description  would  be  superfluous. 

When  a  magneto  is  installed  some  precautions  are  necessary  re- 


366 


The  Modern  Gasoline  Automobile 


lating  to  wiring  and  also  the  character  of  the  spark  plugs  employed. 
The  conductor  should  be  of  good  quality,  have  ample  insulation  and 
be  well  protected  from  accumulations  of  oil  which  would  tend  to 
decompose  rubber  insulation.  It  is  customary  to  protect  the  wiring 
by  running  it  through  the  conduits  of  fiber  or  metal  tubing  lined  with 


Connections  for  the  Bosch 
Dual  Ignition 


*  Thin  blue  cable  for  battery  contact  fcreaker. 
2  Thin  red  cable forshort  circuiting  terminal. 


•shor    „  „ _.. 

n-  v  n-       •  /3  Thick  white  cable  for  high  tension  terminal. 

High  Tension     -^4  Thick  .brown  cable  for  distributor  terminal.. 

Single  Connections: 

T  nw  Tpnsinn         / 1  and  5-  To  tlle  terminals  of  the  battery. 
Low  Tension         {  Connection  to  the  frame. 


Fig.  207. — Method  of  Applying  Bosch  Dual  Ignition  System  to  Conventional 
Four-Cylinder  Power  Plant. 

insulating  material.  Multiple  strand  cables  should  be  used  for  both 
primary  and  secondary  wiring  and  the  insulation  should  be  of  rubber 
at  least  T3-g-  inch  thick. 

The  spark  plugs  commonly  used  for  battery  and  coil  ignition  can- 
not always  be  employed  when  a  magneto  is  fitted.  The  current  pro- 
duced by  the  mechanical  generator  has  a  greater  amperage  and  more 
heat  value  than  that  obtained  from  transformer  coils  excited  by  battery 
current.  The  greater  heat  may  burn  or  fuse  the  slender  points  used^ 
on  some  battery  plugs  and  heavier  electrodes  are  needed  to  resist  the 
heating  effect  of  the  more  intense  arc.  While  the  current  has  greater 
amperage  it  is  not  of  as  high  potential  or  voltage  as  that  commonly 
produced  by  the  secondary  winding  of  an  induction  coil,  and  it  cannot 
overcome  as  much  of  a  gap.  Manufacturers  of  magneto  plugs  usually 
set  the  spark  points  about  -fa  °^  an  ^nc^  aPart-  Tne  most  efficient 


The  Modern  Gasoline  Automobile  367 

magneto  plug  has  a  plurality  of  points  so  that  when  the  distance  be- 
tween one  set  becomes  too  -great  the  spark  will  take  place  between 
one  of  the  other  pairs  of  electrodes  which  are  not  separated  by  so  great 
an  air  space. 

Expert  motorists  championed  the  cause  of  mechanical  generators 
of  electricity  some  time  ago,  but  it  is  only  within  the  past  year  or  two 
that  the  public  demand  for  these  devices  impelled  manufacturers  of 
motor  cars  to  supply  them  as  regular  equipment  on  their  cars. 


CHAPTEE    VII 

Reason  for  Lubrication  of  Mechanism — Lubricants  and  their  Derivation — 
Methods  of  Supplying  Oil — Typical  Lubrication  Systems  Outlined — Theory 
and  Functions  of  Cooling  Systems — Water-Cooling  Methods  Explained — 
Elements  of  Simple  Circulating  System — Forced  Circulation  and  Apparatus 
— Thermosyphon-Cooling  Methods — Air-Cooling  Systems. 

THE  importance  of  minimizing  friction  at  the  various  bearing  sur- 
faces of  machines  to  secure  mechanical  efficiency  is  fully  recognized 
by  all  mechanics,  and  proper  lubricity  of  all  parts  of  the  mechanism 
is  a  very  essential  factor  upon  which  the  durability  and  successful 
operation  of  the  motor  car  power  plant  depends.  All  of  the  moving 
members  of  the  engine  which  are  in  contact  with  other  portions,, 
whether  the  motion  is  continuous  or  intermittent,  of  high  or  low 
velocity  or  of  rectilinear  or  continued  rotary  nature,  should  be  pro- 
vided with  an  adequate  supply  of  oil.  No  other  assemblage  of  mech- 
anism is  operated  under  conditions  which  are  so  much  to  its  disad- 
vantage as  the  motor  car,  and  the  tendency  is  toward  a  simplification 
of  oiling  methods  so  that  the  supply  will  be  ample  and  automatically 
applied  to  the  points  needing  it. 

In  all  machinery  in  motion  the  members  which  are  in  contact 
have  a  tendency  to  stick  to  each  other  and  the  very  minute  projections 
which  exist  on  even  the  smoothest  of  surfaces  would  have  a  tendency 
to  cling  or  adhere  to  each  other  if  the  surfaces  were  not  kept  apart  by 
some  elastic  and  unctuous  substance.  This  will  flow  or  spread  out 
over  the  surfaces  and  smooth  out  the  inequalities  existing  which  tend 
to  produce  heat  and  retard  motion  of  the  pieces  relative  to  each 
other. 

A  general  impression  which  obtains  is  that  well  machined  sur- 
faces are  smooth  and  while  they  are  apparently  free  from  roughness 
and  no  projections  are  visible  to  the  naked  eye,  any  smooth  bearing 
surface,  even  if  very  carefully  ground,  will  have  a  rough  appearance 
if  examined  with  a  magnifying  glass.  An  exaggerated  condition  to 

368 


The  Modern  Gasoline  Automobile 


369 


illustrate  this  point  is  shown  at  Fig.  208.  The  amount  of  friction 
will  vary  in  proportion  to  the  pressure  on  the  surfaces  in  contact  and 
will  augment  as  the  loads  increase,  the  rougher  surfaces  will  have 
more  friction  than 'smoother  ones  and  soft  bodies  will  produce  more 
friction  than  hard  substances. 


Pillow  Block 


Magnified 
Shaft 


Magnifying  Glass 


Fig.  208. — Showing  Use  of  Magnifying  Glass  to  Demonstrate  that  Apparently 
Smooth  Metal  Surfaces  May  Have  Minute  Irregularities  which  Produce 
Friction. 

Friction  is  always  present  in  any  mechanism  as  a  resisting  force 
that  tends  to  retard  motion  and  bring  all  moving  parts  to  a  state  of 
rest.  The  absorption  of  power  by  friction  may  be  gauged  by  the 
amount  of  heat  which  exists  at  the  bearing  points.  Friction  of  solids 
may  be  divided  into  two  classes,  sliding  friction,  such  as  exists  be- 
tween the  piston  and  cylinder,  or  the  bearings  of  a  gas  engine  and 
rolling  friction,  which  is  that  present  when  the  load  is  supported  by 
ball  or  roller  bearings  or  that  which  exists  between  the  tires  or  the 
driving  wheels  and  the  road.  Engineers  endeavor  to  keep  friction 


370  The  Modern  Gasoline  Automobile 

losses  as  low  as  possible  and  much  care  is  taken  in  all  modern  auto- 
mobiles to  provide  adequate  methods  of  lubrication,  or  anti-friction 
bearings  at  all  points  where  considerable  friction  exists. 

Theory  of  Lubrication. — The  reason  a  lubricant  is  supplied  to  bear- 
ing points  will  be  easily  understood  if  one  considers  that  these  elastic 
substances  flow  between  the  close  fitting  surfaces,  and  by  filling  up  the 
minute  depressions  in  the  surfaces  and  covering  the  high  spots  act  as 
a  cushion  which  absorbs  the  heat  generated  and  takes  the  wear  instead 
of  the  metallic  bearing  surface.  The  closer  the  parts  fit  together  the 
more  fluid  the  lubricant  must  be  to  pass  between  their  surfaces  and 
at  the  same  time  it  must  possess  sufficient  body  so  that  it  will  not  be 
entirely  forced  out  by  the  pressure  existing  between  the  parts. 

Oils  should  have  good  adhesive,  as  well  as  cohesive,  qualities.  The 
former  are  necessary  so  that  the  oil  film  will  cling  well  to  the  surfaces 
of  the  bearings ;  the  latter,  so  the  oil  particles  will  cling  together  and 
resist  the  tendency  to  separation  which  exists  all  the  time  the  bearings 
are  in  operation.  When  used  for  gas-engine  lubrication  the  oil  should 
be  capable  of  withstanding  considerable  heat  in  order  that  it  will  not 
be  vaporized  by  the  hot  portions  of  the  cylinder.  It  should  have  suffi- 
cient cold  test  so  that  it  will  remain  fluid  and  flow  readily  at  low 
temperature.  Lubricants  should  be  free  from  acid,  or  alkalis,  which 
tend  to  produce  a  chemical  action  with  metals  and  result  in  corrosion 
of  the  parts  to  which  they  are  applied.  It  is  imperative  that  the  oil 
be  exactly  the  proper  quality  and  nature  for  the  purpose  intended  and 
that  it  be  applied  in  a  positive  manner.  The  requirements  may  be 
briefly  summarized  as  follows : 

First — It  must  have  sufficient  body  to  prevent  seizing  of  the 
parts  to  which  it  is  applied  and  between  which  it  is  depended  upon 
to  maintain  an  elastic  film,  and  yet  it  must  not  have  too  much  viscos- 
ity in  order  to  minimize  the  internal  or  fluid  friction  which  exists 
between  the  particles  of  the  lubricant  itself. 

Second — The  lubricant  must  not  coagulate  or  gum,  must  not  in- 
jure, the  parts  to  which  it  is  applied,  either  by  chemical  action  or  by 
producing  injurious  deposits,  and  it  should  not  evaporate  readily. 

Third — The  character  of  the  work  will  demand  that  the  oil  should 
not  vaporize  when  heated  or  thicken  to  such  a  point  that  it  will  not 
flow  readily  when  cold. 


The  Modern  Gasoline  Automobile  371 

Fourth — The  oil  must  be  free  from  acid,,  alkalis,  animal  or  vege- 
table fillers,  or  other  injurious  agencies. 

Fifth — It  must  be  carefully  selected  for  the  work  required  and 
should  be  a  good  conductor  of  heat. 

Derivation  of  Lubricants. — The  first  oils  which  were  used  for  lubri- 
cating machinery  were  obtained  from  animal  and  vegetable  sources, 
though  at  the  present  time  most  unguents  are  of  mineral  derivation. 
Lubricants  may  exist  as  fluids,  semifluids,  or  solids.  The  viscosity 
will  vary  from  light  spindle  or  dynamo  oils  which  have  but  little 
more  body  than  kerosene  to  the  heaviest  greases  and  tallows.  The 
most  common  solid  employed  as  a  lubricant  is  graphite,  sometimes 
termed  "  plumbago  "  or  "  black  lead."  This  substance  is  of  mineral 
derivation. 

The  disadvantage  of  oil  of  organic  origin,  such  as  those  obtained 
from  animal  fats  or  vegetable  substances,  is  that  they  will  absorb 
oxygen  from  the  atmosphere  which  causes  them  to  thicken  or  become 
rancid.  Such  oils  have  a  very  poor  cold  test  as  they  solidify  at  com- 
paratively high  temperatures  and  their  flashing  point  is  so  low  that 
they  cannot  be  used  at  points  where  much  heat  exists.  In  most  ani-* 
mal  oils  various  acids  are  present  in  greater  or  less  quantities,  and 
for  this  reason  they  are  not  well  adapted  for  lubricating  metallic 
surfaces  which  may  be  raised  high  enough  in  temperature  to  cause 
decomposition  of  the  oils. 

Lubricants  derived  from  the  crude  petroleum  are  called  "  Oleo- 
napthas  "  and  they  are  a  product  of  the  process  of  refining  petroleum 
through  which  gasoline  and  kerosene  are  obtained.  They  are  of 
lower  cost  than  vegetable  or  animal  oil  and  as  they  are  of  nonorganic 
origin  they  do  not  become  rancid  or  gummy  by  constant  exposure  to 
the  air  and  they  will  have  no  corrosive  action  on  metals  because  they 
contain  no  deleterious  substances  in  chemical  composition.  By  the 
process  of  fractional  distillation  mineral  oils  of  all  grades  can  be 
obtained.  They  have  a  lower  cold  and  higher  flash  test  and  there  is 
not  the  liability  of  spontaneous  combustion  that  exists  with  animal 
oils. 

The  organic  oils  are  derived  from  fatty  substances  which  are 
present  in  the  bodies  of  all  animals  and  in  some  portions  of  plants. 
The  general  method  of  extracting  oil  from  animal  bodies  is  by  a  ren- 


372  The  Modern  Gasoline  Automobile 

dering  process  which  consists  of  applying  sufficient  heat  to  liquefy 
the  oil  and  then  separating  it  from  the  tissue  with  which  it  is  com- 
bined by  compression.  The  only  oil  which  is  used  to  any  extent  in 
gas-engine  lubrication  that  is  not  of  mineral  derivation  is  castor  oil. 
This  substance  has  been  used  on  high-speed  racing  automobile  engines 
and  on  aeroplane  power  plants.  It  is  obtained  from  the  seeds  of  the 
castor  plant  which  contain  a  large  percentage  of  oil. 

Among  the  solid  substances  which  may  be  used  for  lubricating 
purposes  may  be  mentioned  tallow,  which  is  obtained  from  the  fat  of 
animals,  and  graphite  and  soapstone,  which  are  of  mineral  derivation. 
Tallow  is  never  used  at  points  where  it  will  be  exposed  to  much 
heat,  though  it  is  often  employed  as  a  filler  for  greases  used  in  trans- 
mission gearing.  Graphite  is  sometimes  mixed  with  oil  and  applied 
to  cylinder  lubrication,  though  it  is  most  often  used  in  connection 
with  greases  in  the  running  gear  parts.  Graphite  is  not  affected  by 
heat,  cold,  acids,  or  alkalis  and  has  a  strong  attraction  for  metal  sur- 
faces. It  mixes  readily  with  oils  and  greases  and  increases  their 
efficiency  in  many  applications.  It  is  sometimes  used  where  it  would 
not  be  possible  to  use  other  lubricants  because  of  extremes  of  tempera- 
ture. Graphite  can  be  applied  to  advantage  to  practically  all  portions 
of  the  motor-car  mechanism. 

The  oils  used  for  cylinder  lubrication  are  obtained  almost  ex- 
clusively from  crude  petroleum  derived  from  American  wells.  Special 
care  must  be  taken  in  the  selection  of  the  crude  material,  as  every 
variety  will  not  yield  oil  of  the  proper  quality  to  be  used  as  a  cylinder 
lubricant.  The  crude  petroleum  is  distilled  as  rapidly  as  possible 
with  fire  heat  to  vaporize  off  the  naphthas  and  the  burning  oils.  After 
these  vapors  have  been  given  off  superheated  steam  is  provided  to 
assist  in  distilling.  When  enough  of  the  light  elements  have  been 
eliminated  the  residue  is  drawn  off,  passed  through  a  strainer  to  free 
it  from  grit  and  earthy  matters,  and  is  afterwards  cooled  to  separate 
the  wax  from  it.  This  is  the  dark  cylinder  oil  and  is  the  grade 
usually  used  for  steam-engine  cylinders. 

The  oil  that  is  to  be  used  in  the  gasoline  engine  must  be  of  high 
quality  and  for  that  reason  the  best  grades  are  distilled  in  a  vacuum 
that  the  light  distillates  may  be  separated  at  much  lower  temperatures 
than  ordinary  conditions  of  distilling  permit.  If  the  degree  of  heat 


The  Modern  Gasoline  Automobile  373 

is  not  high  the  product  is  not  so  apt  to  decompose  and  deposit  carbon. 
If  it  is  desired  to  remove  the  color  of  the  oil  which  is  caused  by 
free  carbon  and  other  impurities  it  can  be  accomplished  by  filtering 
the  oil  through  charcoal.  The  greater  the  number  of  times  the  oil  is 
filtered,  the  lighter  it  will  become  in  color.  The  best  cylinder  oils 
have  flash  points  usually  in  excess  of  500  degrees  F.  and  while  they 
have  a  high  degree  of  viscosity  at  100  degrees  F.  they  become  more 
fluid  as  the  temperature  increases. 

The  lubricating  oils  obtained  by  refining  crude  petroleum  may  be 
divided  into  three  classes: 

First — The  natural  oils  of  great  body  which  are  prepared  for  use 
by  allowing  the  crude  material  to  settle  in  tanks  at  high  temperature 
and  from  which  the  impurities  are  removed  by  natural  filtration. 
These  oils  are  given  the  necessary  body  and  are  free  from  the  volatile 
substances  they  contain  by  means  of  superheated  steam  which  provides 
a  source  of  heat. 

Second — Another  grade  of  these  natural  oils  which  are  filtered 
again  at  high  temperatures  and  under  pressure  through  beds  of  animal 
charcoal  to  improve  their  color. 

Third — Pale,  limpid  oils,  obtained  by  distillation  and  subsequent 
chemical  treatment  from  the  residuum  produced  in  refining  petroleum 
to  obtain  the  fuel  oils. 

Authorities  agree  that  any  form  of  mixed  oil  in  which  animal  and 
mineral  lubricants  are  combined  should  never  be  used  in  the  cylinder 
of  a  gas  engine  as  the  admixture  of  the  lubricants  does  not  prevent 
the  decomposition  of  the  organic  oil  into  the  glycerides  and  fatty 
acids  peculiar  to  the  fat  used.  In  a  gas-engine  cylinder  the  flame 
tends  to  produce  more  or  less  charring.  The  deposits  of  carbon  will 
be  much  greater  with  animal  oils  than  with  those  derived  from  the 
petroleum  base  because  the  constituents  of  a  fat  or  tallow  are  not  of 
the  same  volatile  character  as  those  which  comprise  the  hydrocarbon 
oils  which  will  evaporate  or  volatilize  before  they  char  in  most  in- 
stances. 

A  suitable  lubricant  for  gas-engine  cylinders  is  a  pure  hydrocar- 
bon oil  having  a  high  vaporizing  point,  about  200  degrees  F.,  a  flash 
point  of  430  degrees  F.,  and  a  fire  test  of  about  600  degrees  F.  It  is 
fortunate  that  many  brands  of  good  oils  may  be  obtained  at  the  pres- 


374  The  Modern  Gasoline  Automobile 

ent  time  and  in  this  connection  it  is  well  to  state  that  the  best  oil  is 
none  too  good  for  the  motor-car  engine  cylinders.  There  is  an  im- 
pression among  many  motorists  of  economical  tendencies  that  any  oil 
will  answer  and  that  the  cheapest  is  obviously  best  because  it  costs 
less.  A  point  that  cannot  be  too  strongly  impressed  upon  all  who 
have  machinery  of  any  description  in  their  care  is  that  efficient  opera- 
tion can  only  be  obtained  by  selecting  proper  lubricant,  and  that  high 
quality  oils  can  only  be  obtained  by  paying  for  them.  In  this  appli- 
cation the  old  adage,  "  The  best  is  the  cheapest  in  the  end/'  is  par- 
ticularly apropos. 

Devices  for  Supplying  Lubricant. — The  method  of  supplying  the 
lubricant  will  depend  largely  upon  the  nature  of  the  part  to  be  oiled 
as  well  as  the  character  of  the  oily  medium.  The  various  parts  of 
the  internal  combustion  engine  demand  continued  lubrication  and 
means  must  be  provided  which  will  insure  positive  supply  of  lubricant 
in  measured  quantities  for  more  or  less  extended  periods.  Engine 
lubricators  should  be  positive  in  action  and  not  liable  to  be  affected 
by  varying  weather  conditions.  The  lubricant  should  not  be  supplied 
in  excess  and  in  some  systems  it  is  desirable  that  the  feeds  be  ad- 
justed as  desired  and  independently  of  each  other. 

Any  oiling  device  should  be  as  nearly  automatic  in  action  as  pos- 
sible and  the  modern  types  require  but  little  further  attention  from 
the  motorist  than  to  keep  a  proper  amount  of  lubricant  in  the  con- 
tainer. The  oil  feed  to  the  moving  parts  should  start  as  soon  as  the 
engine  begins  to  turn  and  the  supply  should  be  interrupted  when  the 
mechanism  stops.  The  only  system  which  combines  all  the  desirable 
features  is  that  which  includes  a  mechanical  drive  from  the  source 
of  power.  Lubricators  may  be  divided  into  two  classes,  those  which 
depend  upon  natural  phenomena  such  as  the  attraction  of  gravity  or 
displacement  by  air  pressure,  and  others  which  are  worked  by  mechan- 
ical means  and  which  deliver  the  oil  in  measured  quantities  by  posi- 
tively driven  pumps. 

The  simplest  form  of  lubricating  appliance  is  that  in  which  oil  is 
carried  in  a  tank  or  oil  cup  placed  higher  than  the  points  to  which 
it  is  applied  and  then  delivered  to  the  bearing  points  in  drops.  A 
simple  form  of  sight-feed  gravity  oiler  is  shown  at  Fig.  209,  A.  This 
device  has  a  glass  body  so  that  the  amount  of  oil  at  the  disposal  of 


The  Modern  Gasoline  Automobile 


375 


the  motorist  ma}r  be  instantly  noted  and  two  sight-feed  gauges  at  the 
bottom  which  are  connected  to  the  points  needing  lubricant.  The 
opening  through  which  the  oil  drips  is  regulated  by  an  adjustable 
knurled  screw  which  turns  a  needle  controlling  the  supply  orifice.  In 


Shut-off. 


Adjustment. 


Filler. 


Glass  Body. 


Adjustment. 


Fig.  209.— Simple  Gravity-Feed  Oil  Cups  with  Glass  Body  to  Show  Height  of 
Lubricant  in  Container,  and  Sight  Gauges  to  Give  Visible  Evidence  of 
Amount  of  Oil  Supplied. 

connection  with  the  adjustable  feature  a  simple  lever  is  usually  pro- 
vided by  which  the  needle  may  be  raised  from  its  seat  and  the  oil 
allowed  to  flow  into  the  sight-feed  glass. 

In  the  device  shown  at  A  the  shut-off  lever,  which  is  horizontally 
placed,  allows  the  needle  to  seat  against  the  opening  in  the  bottom  of 
the  lubricator  and  the  flow  of  oil  is  stopped.  When  placed  vertically, 
as  shown  at  the  right,  the  needle  is  raised  from  its  seat  and  the  oil 


376  The  Modern  Gasoline  Automobile 

may  flow  to  the  part  with  which  the  sight-feed  glass  is  coupled. 
When  more  than  two  feeds  are  desired,  the  oil  from  the  main  con- 
tainer may  drip  into  a  manifold  fitting  which  will  have  any  desired 
number  of  sight-feed  glasses  and  their  individual  connections.  m  A 
gravity  oiler  having  four  sight-feed  glasses  is  depicted  at  Fig.  209,  B. 

A  disadvantage  of  oilers  which  depend  upon  gravity  is  that  great 
care  must  be  exercised  in  selecting  lubricant  which  will  have  the 
proper  viscosity  or  body  to  flow  under  the  specific  conditions  of  oper- 
ation which  may  obtain  at  different  times.  For  instance,  during 
warm  weather  oil  will  flow  readily  and  heavier  bodied  lubricants  may 
be  used  without  danger  of  clogging  the  supply  pipe  or  the  opening 
in  the  body  of  the  oiler.  When  the  weather  becomes  colder  the 
oil  may  congeal  and  lighter  fluid  must  be  supplied  to  maintain  an  un- 
interrupted feed.  Should  the  oil  leads  to  the  bearing  become  clogged 
by  a  particle  of  foreign  matter  the  oil  feed  will  be  interrupted  be- 
cause the  weight  of  the  oil  is  not  sufficient  to  dislodge  the  particle 
which  hinders  its  flow.  The  result  is  that  no  oil  reaches  the  bearing 
point  and  the  part  which  needs  the  lubricant  will  be  deprived  of  oil 
and  cause  trouble. 

With  devices  of  this  form  it  is  necessary  to  frequently  manipulate 
the  adjustments.  Every  atmospheric  change  that  causes  a  difference 
of  temperature  must  be  reckoned  with,  and  if  the  oiler  is  adjusted 
during  cold  weather  it  will  feed  too  fast  when  the  temperature  is 
higher.  If  the  supply  of  oil  is  regulated  during  warm  weather  when 
the  oil  flows  easily,  as  soon  as  the  lubricant  congeals  it  will  not  pass 
through  the  supply  pipes  so  -readily  and  the  opening  must  be  in- 
creased in  area  to  compensate  for  the  greater  viscosity  of  the  lubri- 
cant. The  gravity  oiler  is  seldom  used  in  modern  automobiles  and  is 
only  found  on  cars  of  early  vintage  which  are  still  in  use  in  large 
numbers  in  some  parts  of  the  country.  It  is  utilized  to  some  extent 
in  marine  applications  where  it  can  be  mounted  very  close  to  the 
engine  and  kept  at  a  uniform  temperature  by  the  heat  given  off  from 
the  power  plant. 

Mechanical  Oiling  Methods  Described. — The  oiling  systems  of  the 
late  forms  of  motor  cars  depend  upon  some  positive  oil  pump  to  main- 
tain circulation  of  the  lubricant  or  to  force  it  to  the  bearing  point. 
Two  forms  of  pumps  are  shown  in  section  at  Fig.  210.  That  at  A  is 


The  Modern  Gasoline  Automobile 


377 


a  simple  plunger  pump  in  which  the  plunger  is  operated  by  means  of 
a  cam  driven  by  worm  gearing  from  some  suitable  point  on  the  power 
plant.  When  the  pump  plunger  is  drawn  out  toward  the  end  of  the 
cylijider  the  suction  lifts  the  inlet  check  valve,  which  is  a  small  steel 
ball,  from  its  seat  and  the  pump  cylinder  fills  with  oil.  On  the  down- 


worm  Gear 

Sight  Feecb 


Worm 


Relief  Ch 

Cam. 

Pump  Cylinder. 
Pump  Plunger. 


B 

Bypass. 


Pump  Body. 


Outlet 
Check  Valve. 


Disch 

f~—  Worm  Drive  Shaft. 
Inlet  Check  Valve. 


Pump  Gears. 


Fig.  210. — Positive  Mechanical  Methods  of  Supplying  Lubricant.  A — Worm 
Gear  Driven  Plunger  Pump  Oiler.  B — Gear  Pump  with  High-Pressure 
Relief  Valve. 

stroke  of  the  pump  plunger  the  outlet  qheck  valve  is  unseated  by  the 
oil  pressure  and  the  lubricant  is  expelled  from  the  pump  cylinder  to 
the  bearing  point  in  a  positive  manner  and  under  some  degree  of 
pressure.  The  stroke  of  the  pump  plunger  may  be  varied  by  a  suit- 
able adjustment  and  the  quantity  of  oil  directed  to  the  bearing  point 
will  depend  upon  the  stroke  of  the  pump  plunger.  Most  forms  of 
the  device  described  use  a  multiplicity  of  pumps  and  individual  leads 
to  the  different  bearing  points.  The  arrangement  is  such  that  each 
bearing  is  served  by  its  own  pump  member. 

In  other  systems  a  single  pump  of  large  capacity  is  used,  this 
supplying  oil  to  a  manifold  fitting  from  which  it  is  distributed  to  the 
cylinders  or  to  the  engine  base  from  which  it  is  picked  up  and 
splashed  about  by  fingers  on  the  bottom  of  the  connecting  rods.  An- 
other form  of  pump  which  is  used  more  in  maintaining  circulation 
of  oil  in  systems  where  distribution  is  by  connecting  rods  than  in 
individual  supply  systems  is  shown  at  B.  One  of  a  pair  of  gears  is 
driven  by  the  engine  and  turns  the  other  one  so  that  the  oil  which 


378 


The  Modern  Gasoline  Automobile 


fills  the  pump  body  is  entrapped  in  spaces  between  the  teeth  of  the 
gears  and  forced  along  through  the  discharge  pipe.  The  form  of 
pump  shown  has  a  ball  check  valve  which  seats  against  an  opening 
which  communicates  with  the  discharge  pipe.  Should  there  be  an 
obstruction  in  the  piping  which  will  result  in  excessive  pressure  the 
relief  valve  will  unseat  and  the  pressure  will  be  diminished  by  a  quan- 
tity of  the  oil  flowing  back  into  the  inlet  end  through  the  by-pass 
passage. 

Two  methods  of  distributing  oil  in  the  interior  of  internal  com- 
bustion engines  are  outlined  at  Fig.  211.     That  at  A  consists  in  pro- 


C-rank-shaft. 


Bearing. 


Tilting  Oil  Trough. 


Fig.  211. — How  Oil  May  be  Supplied  to  Interior  Mechanism  of  Internal  Com- 
bustion Motor.  A — Oil  Pick-up  Finger  on  Connecting  Rod  End  Dips  into 
Lubricant  and  Splashes  It  Over  Interior  Parts.  B — Oil  Drops  into  Channel 
in  Horizontal  Connecting  Rod  and  Supplies  Bearings  and  Cylinder. 

viding  an  oil  pick-up  finger  or  splasher  at  the  bottom  of  the  connecting 
rod  big  end  which  dips  into  the  lubricant  carried  in  an  oil  trough 
directly  under  the  connecting  rod.  As  the  crank  shaft  revolves  in 
the  direction  of  the  arrow,  a  certain  amount  of  lubricant  will  be 
picked  up  from  the  trough  and  as  the  speed  increases  the  rapid  move- 
ment of  the  pick-up  finger  through  the  oil  will  splash  it  around  the 
interior  of  the  motor  base.  The  form  of  oil  trough  shown  is  that 
used  on  the  Knight  engines  and  it  is  supported  at  one  end  on  a 
bearing  rod  which  is  interconnected  with  the  throttle  so  that  as  the 
gas  supply  is  opened  up  to  accelerate  the  engine,  the  oil  trough  is 
tilted  in  such  a  way  that  the  proper  quantity  of  lubricant  will  be 
supplied  the  cylinder. 


The  Modern  Gasoline  Automobile  379 

A  simple  method  which  is  applicable  on  engines  having  horizon- 
tally disposed  cylinders  is  outlined  at  Fig.  211,  B.  In  this  the  oil  is 
applied  to  a  point  about  midway  in  the  cylinder  and  in  such  a  position 
that  it  is  swept  by  the  piston  on  its  up  or  downstroke.  When  in  the 
position  shown  in  the  drawing  the  piston  is  traveling  toward  the  open 
end  of  the  cylinder,  and  until  the  oil  hole  is  shut  off  by  the  wall  of 
the  piston  the  lubricant  will  drip  directly  into  the  bottom  of  a  U  sec- 
tion connecting  rod.  When  the  rod  is  at  the  angle  shown  the  oil 
will  flow  to  the  crank-pin  bearings.  When  the  piston  reaches  a  point 
in  the  cylinder  so  that  the  copper  tube  carried  by  it  registers  with  the 
oil  opening  the  stream  of  lubricant  will  pass  through  the  copper  tube 
and  onto  the  wrist  pin.  The  cylinder  wall  and  other  points  which 
need  oiling  are  kept  covered  with  a  film  of  oil  derived  from  the 
spray  or  mist  composed  of  finely  divided  particles  of  oil  which  is 
present  in  the  crank  case  all  times  the  engine  is  in  operation. 

Oil  Supply  by  Constant  Level  Splash  System. — The  splash  system 
of  lubrication  that  depends  on  the  connecting  rod  to  distribute  the 
lubricant  is  one  of  the  most  successful  and  simplest  forms  if  some 
means  of  maintaining  a  constant  level  is  provided.  If  too  much  oil 
is  supplied  the  surplus  will  work  past  the  piston  rings  and  into  the 
combustion  chamber,  where  it  will  bu*n  and  cause  carbon  deposits. 
Too  much  oil  will  also  cause  an  engine  to  smoke  and  an  excess  of 
lubricating  oil  is  usually  manifested  by  a  bluish-white  smoke  issuing 
from  the  exhaust. 

A  good  method  of  maintaining  a  constant  level  of  oil  for  the 
successful  application  of  the  splash  system  is  shown  at  Fig.  212.  The 
engine  base  casting  includes  a  separate  chamber  which  serves  as  an 
oil  container  and  which  is  below  the  level  of  oil  in  the  crank  case. 
The  lubricant  is  drawn  from  the  sump  or  oil  container  by  means  of 
a  positive  oil  pump  which  discharges  directly  into  the  engine  case. 
The  level  is  maintained  by  an  overflow  pipe  which  allows  all  excess 
lubricant  to  flow  back  into  the  oil  container  at  the  bottom  of  the  cyl- 
inder. Before  passing  into  the  pump  again  the  oil  is  strained  or 
filtered  by  a  screen  of  wire  gauze  and  all  foreign  matter  removed. 
Owing  to  the  rapid  circulation  of  the  oil  it  may  be  used  over  and 
over  again  for  quite  a  period  of  time.  The  oil  is  introduced  directly 
into  the  crank  case  by  a  breather  pipe  and  the  level  is  indicated  by 


380 


The  Modern  Gasoline  Automobile 


WaterSpac&s 


fofeke 


Ovejfar/toJl        * — m»**ft 


•Screen 
OirOut/et 


Geared  O// Pu/np 


Fig.  212. — Sectional  View  of  Typical  Motor  Showing  Parts  Needing  Lubrication 
and  Method  of  Applying  Oil  by  Constant  Level  Splash  System.  Note  also 
Water  Jacket  and  Spaces  for  Water  Circulation. 


The  Modern  Gasoline  Automobile 


381 


a  rod  carried  by  a  float  which  rises  when  the  container  is  replenished 
and  falls  when  the  available  supply  diminishes. 

The  system  depicted  at  Fig.  213  is  very  similar  to  that  previously 
described,  except  that  the  oil  feed  from  the  pump  is  first  directed 
into  an  oil  manifold  pipe  from  which  leads  connect  to  the  various 
main  bearings  of  the  engine.  The  oil  dripping  from  these  journals 
collects  in  the  crank  case  until  it  reaches  a  certain  level  and  then 


Level  Indicator 
Pump  Drive  Shaft 


Float 


Fig.  213. — Sectional  View  of  Part  of  Rutenber  Engine  Depicting  Method  of 
Driving  Oil  Pump  and  Distribution  to  Bearing  Points. 

drains  back  into  the  sump  or  oil  container  through  suitable  overflow 
openings.  The  ends  of  the  connecting  rods  are  provided  with  scoops 
or  oil  pick-up  members  which  splash  the  lubricant  around  the  interior 
of  the  engine.  The  amount  of  oil  available  is  shown  by  a  float  con- 
trolled indicator.,  as  in  the  previously  described  system.  The  pump 
is  driven  from  the  cam  shaft  by  means  of  a  pair  of  spiral  gears. 

It  will  be  noted  that  with  such  system  the  only  apparatus  required 
besides  the  oil  tank  which  is  cast  integral  with  the  bottom  of  the 
crank  case  is  a  suitable  pump  to  maintain  circulation  of  oil.  This 
member  is  always  positively  driven,  either  by  means  of  chains  and 
sprockets,  shaft  and  universal  coupling,  or  direct  gearing.  As  the 


382 


The  Modern  Gasoline  Automobile 


pump  is  used  to  circulate  oil  but  little  wear  will  result  during  the  life 
of  the  engine  because  all  parts  of  the  pump  mechanism  are  operating 
in  a  constant  bath  of  lubricant.  The  screens  or  filters  are  usually  in- 


Distributing  Manifold 


Fig.  214. — Oil  Distributing  System  Employed  on  Stoddard-Dayton  Motor  Cars. 

stalled  at  points  which  will  permit  them  to  be  easily  removed  when 
cleaning  is  necessary. 

The  self-contained  oiling  systems  of  the  constant  level  type  greatly 
simplify  the  power  plant  and  insure  the  economical  use  of  lubricant. 
The  proper  level  of  oil  is  regulated  at  the  factory  by  the  position  of 
the  overflow  pipes  and  it  must  remain  in  adjustment  because  there 
is  no  way  of  altering  it  on  most  motors.  As  the  lubricating  oil  is 
carried  in  the  bottom  of  the  engine  case  it  is  heated  up  as  soon  as  the 
engine  has  been  in  operation  for  a  few  moments,  and  as  the  viscosity 
of  the  lubricant  cannot  be  altered  by  varying  conditions  of  tempera- 
ture or  climate  the  same  grade  of  oil  may  be  employed  during  the 
entire  year.  Other  advantages  are  that  the  lubricating  system  is 


The  Modern  Gasoline  Automobile 


383 


entirely  automatic  in  action,  that  it  will  furnish  a  positive  supply  of 
oil  at  all  desired  points,  and  that  it  cannot  be  tampered  with  by  the 
inexpert  motorist  because  no  adjustments  are  provided  or  needed. 

The  constant  level  system  may  be  modified  in  a  number  of  re- 
spects. Sometimes  the  oil  is  fed  directly  to  the  crank  case  compart- 
ment and  the  connecting  rods  depended  upon  solely  to  distribute  the 
lubricant.  In  other  systems,  the  oil  delivered  by  the  pump  is  con- 
veyed to  a  distributing  manifold,,  as  shown  at  Fig.  214.  From  this 


Fig.  215.— Part  Sectional  View  of  Motor-Car  Engine  Showing  Oil  Distribution 
by  Splashers  at  the  Ends  of  the  Connecting  Rods,  which  Dip  into  Troughs 
Disposed  Under  Them. 

manifold  member  the  oil  is  delivered  to  important  bearing  points, 
such  as  the  main  journals,  and  directly  to  the  cylinder  walls  by  small 
copper  pipes  before  it  is  allowed  to  drain  back  into  the  crank  case  and 


384 


The  Modern  Gasoline  Automobile 


from  this  member  overflow  into  the  sump  or  container.  In  some  sys- 
tems no  separate  oil  container  is  cast  with  the  crank  case,  this  mem- 
ber being  made  deeper  so  that  the  oil  level  will  be  below  the  point 
where  the  connecting  rods  will  pass  through  it.  When  this  practice 
is  followed  small  troughs  are  cast  in  the  engine  base  into  which  the 
scoops  on  the  connecting  rod  dip,  as  shown  at  Fig.  215. 

Distributing  Lubricant  by  Pressure.— In  some  power  plants  it  is 
considered  desirable  to  supply  the  oil  directly  to  the  parts  needing 


Automatic 
Speed  Governor 


Oil  Supp/y 

76  FrontMa/n 

Beotrtnq 


To  Center 
Beacrtny 


Git  Pump 


Fig.  216. — Method  of  Supplying  Oil  Under  Pressure  to  Main  Bearings,  from 
which  It  is  Directed  to  Connecting  Rods  by  Passages  Drilled  in  Crank  Shaft. 

it  by  suitable  leads  instead  of  depending  solely  upon  the  distributing 
action  of  scoops  on  the  connecting  rod  big  ends.  A  system  of  this 
nature  is  shown  at  Fig.  216.  The  oil  is  carried  in  the  crank  case  as 
is  common  practice,  but  the  normal  oil  level  is  below  the  point  where 
it  will  be  reached  by  the  connecting  rod.  It  is  drawn  from  the  crank 
case  by  a  plunger  pump  which  directs  it  to  a  manifold  leading 
directly  to  conductors  which  supply  the  main  journals.  After  the 
oil  has  been  used  on  these  points  it  drains  back  into  the  bottom  of 
the  crank  case.  An  excess  is  provided  which  is  supplied  to  the  con- 


Tlie  Modern  Gasoline  Automobile 


385 


necting  rod  ends  by  passages  drilled  into  the  webs  of  the  crank 
shaft  and  part  way  into  the  crank  pins  as  shown  by  the  dotted  lines. 
The  oil  which  is  present  at  the  connecting  rod  crank  pins  is  thrown 
off  by  centrifugal  force  and  lubricates  the  cylinder  walls  and  other 
internal  parts.  Small  cups  are  cast  at  the  upper  end  of  the  con- 
necting rods  to  collect  oil,  and  suitable  passages  allow  the  lubricant 
to  flow  between  the  wrist  pin  and  wrist-pin  bushing. 

Individual  pump  oilers  are  not  so  widely  used  at  the  present  time 
as  they  have  been  in  the  past,  but  a  number  of  designers  still  contend 
that  these  devices  are  superior  to  the  simpler  splash  systems  because 
only  clean  oil  is  delivered  to  the  bearing  points  and  in  measured 
quantities.  It  is  contended  that  with  splash  systems  the  oil  soon 
becomes  impregnated  with  minute  carbon  particles  and  that  it  is  not 
as  suitable  for  lubricating  purposes  as  the  clean  lubricant  supplied 


Cylinder  No.  4 
'   Cylinder  No.  3 

Rear  Crank  Case. 
Front  Crank  Case. 
'  Cylinder  No.  2 
/  ^Cylinder  No.  1. 

—Regulating 
Screws. 

Check  Valve. 


Overflow. 


Crank  Case. 

Oil  Gage 
Stand  Pii 

Oil  Gage  Cock. 


Oil  Drain  Cock. 


Main  Pump, 
dividual  Pumps- 


Fig.  217. — Showing  Application  of  Mechanical  Oiler  having  Individual  Pumps 
and  Leads  to  Bearing  Points  in  Connection  with  Sight-Feed  Gauge  on  Dash. 

from  the  mechanical  oiler.  In  most  systems  where  a  mechanical 
oiler  is  employed  the  splash  system  is  depended  upon  to  a  certain  ex- 
tent as  well,  so  that  it  is  not  readily  apparent  how  the  disadvantage 
cited  can  be  applied  in  favor  of  the  individual  pump  method  of  supply. 
A  typical  system  using  a  mechanical  oiler  is  outlined  at  Fig.  217. 
In  this  one  main  pump  supplies  a  manifold  fitting  carried  on  the 


386  The  Modern  Gasoline  Automobile 

dashboard  from  which  the  oil  drips  into  sight  gauges  through  needle- 
valve  regulated  orifices.  A  series  of  smaller  individual  pumps  draw 
the  oil  from  the  sight-feed  manifold  and  force  it  through  pipes  which 
communicate  with  the  individual  cylinders  and  with  the  front  and 


Main  Feed. 
Oil  Strainer. 
Adjusting-  Valve. 
Oil  Filler. 


Fig.  218. — Oil-Supply  System  Utilized  on  Knox  Automobile  Power  Plants  has 

Many  Good  Features. 

rear  crank  case  compartments  respectively.  Kegulating  screws  are 
provided  so  that  the  amount  of  oil  supplied  the  different  points  may 
be  regulated  at  will.  A  relief  check  valve  is  installed  to  take  care  of 
excess  lubricant  and  to  allow  any  oil  that  does  not  pass  back  into 
the  individual  pumps  to  overflow  into  the  main  container. 

Two  typical  systems  in  which  the  oil  is  first  supplied  to  the  main 
bearings  and  from  thence  to  the  connecting  rods  by  means  of  passages 
in  the  crank  shaft  are  shown  at  Figs.  218  and  219.  The  former  is 
used  on  Knox  motor  cars  and  is  shown  graphically  in  a  phantom 
view  of  the  crank  case  in  which  the  oil  passages  are  made  specially 


The  Modern  Gasoline  Automobile 


387 


prominent.  The  oil  is  taken  from  a  reservoir  at  the  bottom  of  the 
engine  base  by  the  usual  form  of  gear  oil  pump  and  is  supplied  to  a 
main  feed  manifold  which  extends  the  length  of  the  crank  case. 
Individual  conductors  lead  to  the  five  main  bearings,  which  in  turn 
supply  the  crank  pins  through  passages  drilled  through  the  crank-shaft 
web.  In  this  power  plant  the  connecting  rods  are  hollow  section 
bronze  castings  and  the  passage  through  the  center  of  the  connecting 
rod  serves  to  convey  the  lubricant  from  the  crank  pins  to  the  wrist 
pins.  The  cylinder  walls  are  oiled  by  the  spray  of  lubricant  thrown 
off  the  revolving  crank  shaft  by  centrifugal  force. 


Fig.  219.— Constant-Level  Positive-Supply  System  Used  in  Columbia  "  Mark 

85  "  Motor. 


The  system  outlined  at  Fig.  219  is  similar  in  principle  to  that 
previously  described.  In  this  view  the  engine  is  shown  in  part  sec- 
tion and  as  the  oil  delivery  pipes  and  conduits  are  shown  by  heavy 


388  The  Modern  Gasoline  Automobile 

black  lines  it  will  not  be  difficult  to  follow  the  oil  from  the  sump  at 
the  bottom  of  the  crank  case  through  the  oil  pump  and  the  leads  to 
the  main  bearing  and  timing  gear  case.  A  sight  gauge  is  shunted 
into  the  main  circuit  and  is  placed  on  the  dash  so  the  motorist  may 
ascertain  at  any  time  if  the  components  of  the  oil  system  are  function- 
ing properly.  A  float  controlled  level  indicator  is  carried  at  the  side 
of  the  crank  case  so  that  one  may  tell  at  a  glance  if  there  is  an  ade- 
quate supply  of  oil  in  the  container. 

Why  Cooling  Systems  Are  Necessary. — The  reader  should  under- 
stand from  preceding  chapters  that  the  power  of  an  internal  combus- 
tion motor  is  obtained  by  the  rapid  combustion  and  consequent  ex- 
pansion of  some  inflammable  gas.  The  operation  in  brief  is  that 
when  air  or  any  other  gas  or  vapor  is  heated,  it  will  expand  and  that 
if  this  gas  is  confined  in  a  space  which  will  not  permit  expansion, 
pressure  will  be  exerted  against  all  sides  of  the  containing  chamber. 
The  more  a  gas  is  heated,  the  more  pressure  it  will  exert  upon  the 
walls  of  the  combustion  chamber  it  confines.  Pressure  in  a  gas  may 
be  created  by  increasing  its  temperature  and  inversely  heat  may  be 
created  by  pressure.  When  a  gas  is  compressed  its  total  volume  is 
reduced  and  the  temperature  is  augmented. 

The  efficiency  of  any  form  of  heat  engine  is  determined  by  the 
power  obtained  from  a  certain  fuel  consumption.  A  definite  amount 
of  energy  will  be  liberated  in  the  form  of  heat  when  a  pound  of  any 
fuel  is  burned.  The  efficiency  of  any  heat  engine  is  proportional  to 
the  power  developed  from  a  definite  quantity  of  fuel  with  the  least  loss 
of  thermal  units.  If  the  greater  proportion  of  the  heat  units  derived 
by  burning  the  explosive  mixture  could  be  utilized  in  doing  useful 
work  the  efficiency  of  the  gasoline  engine  would  be  greater  than  that 
of  any  other  form  of  energizing  power.  There  is  a  great  loss  of  heat 
from  various  causes,  among  which  can  be  cited  the  reduction  of  pres- 
sure through  cooling  the  motor  and  the  loss  of  heat  through  the  ex- 
haust valves  when  the  burned  gases  are  expelled  from  the  cylinder. 

The  loss  through  the  water  jacket  of  the  average  automobile  power 
plant  is  over  50%  of  the  total  fuel  efficiency.  This  means  that  more 
than  half  of  the  heat  units  available  for  power  are  absorbed  and  dis- 
sipated by  "the  cooling  water.  Another  16%  is  lost  through  the 
exhaust  valve,  and  but  33 \%  of  the  heat  units  do  useful  work.  The 


The  Modern  Gasoline  Automobile  389 

great  loss  of  heat  through  the  cooling  systems  cannot  be  avoided, 
as  some  method  must  be  provided  to  keep  the  temperature  of  the 
engine  within  proper  bounds.  It  is  apparent  that  the  rapid  combus- 
tion and  continued  series  of  explosions  would  soon  heat  the  metal  por- 
tions of  the  engine  to  a  red  heat  if  some  means  were  not  taken  to 
conduct  much  of  this  heat  away.  The  high  temperature  of  the  parts 
would  burn  the  lubricating  oil,  even  that  of  the  best  quality,  and  the 
piston  and  rings  would  expand  to  such  a  degree,  especially  when 
deprived  of  oil,  that  they  would  seize  in  the  cylinder.  This  would 
score  the  walls,  and  the  friction  which  ensued  would  tend  to  bind  the 
parts  so  tightly  that  the  piston  would  stick,  bearings  would  be  burned 
out,  the  valves  would  warp,  and  the  engine  would  soon  become  inop- 
erative. 

The  best  temperature  to  secure  efficient  operation  is  one  on  which 
considerable  difference  of  opinion  exists  among  engineers.  The  fact 
that  the  efficiency  of  an  engine  is  dependent  upon  the  ratio  of  heat 
converted  into  useful  work  compared  to  that  generated  by  the  explo- 
sion of  the  gas  is  an  accepted  fact.  It  is  very  important  that  the 
engine  should  not  get  too  hot,  and  at  the  other  hand  it  is  equally 
vital  that  the  cylinder  be  not  robbed  of  too  much  heat.  The  object 
of  cylinder  cooling  is  to  keep  the  temperature  of  the  cylinder  below 
the  danger  point  but  at  the  same  time  to  have  it  as  high  as  possible 
to  secure  maximum  power  from  the  gas  burned. 

Cooling  Systems  Generally  Applied. — There  are  two  general  sys- 
tems of  engine  cooling  in  common  use,  that  in  which  water  is  heated 
by  the  absorption  of  heat  from  the  engine  and  then  cooled  by  air,  and 
the  other  method  in  which  the  air  is  directed  onto  the  cylinder  and 
absorbs  the  heat  directly  instead  of  through  the  medium  of  water. 
When  the  liquid  is  employed  in  cooling  it  is  circulated  through  jackets 
which  surround  the  cylinder  casting  and  the  water  may  be  kept  in 
motion  by  two  methods.  The  one  generally  favored  is  to  use  a  posi- 
tive circulating  pump  of  some  form  which  is  driven  by  the  engine 
to  keep  the  water  in  motion.  The  other  system  is  to  utilize  a  natural 
principle  that  heated  water  is  lighter  than  cold  liquid  and  that  it  will 
tend  to  rise  to  the  top  of  the  cylinder  when  it  becomes  heated  to  the 
proper  temperature  and  cooled  water  takes  its  place  at  the  bottom  of 
the  water  jacket. 


390 


The  Modern  Gasoline  Automobile 


Air-cooling  methods  may  be  by  radiation  or  convection.  In  the 
former  case  the  effective  outer  surface  of  the  cylinder  is  increased 
by  the  addition  of  flanges  or  spines  cast  thereon,  and  the  air  is  de- 
pended on  to  rise  from  the  cylinder  as  heated  and  be  replaced  by 
cooler  air.  When  a  positive  air  draught  is  directed  against  the 
cylinders  by  means  of  a  fan,  cooling  is  by  convection  and  radiation 
both.  Sometimes  the  air  draught  may  be  directed  against  the  cyl- 
inder walls  by  some  form  of  jacket  which  confines  it  to  the  heated 
portions  of  the  cylinder. 

Cooling  by  Positive  Water  Circulation. — A  typical  water-cooling 
system  in  which  a  pump  is  depended  upon  to  promote  circulation 
of  the  cooling  liquid  is  shown  at  Fig.  220,  and  the  components  of  such 
a  group  are  shown  separately  so  the  construction  may  be  more  easily 
understood  at  Fig.  221.  The  radiator  is  carried  at  the  front  end  of 


ftediator 


Valve  Regulating 
Amount  of  Hot 
ater  in  Car- 
buretor 


«Qf3  Drain  Cock 


Fig.  220.— Components  of  Typical  Motor-Car-Cooling  Group  Utilizing  Pump  to 
Maintain  Circulation  of  Liquid.  System  Shown  Used  on  Peerless  Cars 
with  Success. 

the  car  in  most  cases  and  serves  as  a  combined  water  tank  and 
cooler.  It  is  composed  of  an  upper  and  lower  portion  joined  to- 
gether by  a  series  of  pipes  which  may  be  round  and  provided  with  a 
series  of  fmsvto  radiate  the  heat,  or  which  may  be  flat  in  order  to  have 
the  water  pass  through  in  thin  sheets  and  cool  it  more  easily.  Cellu- 


The  Modern  Gasoline  Automobile 


391 


lar  or  honeycomb  coolers  are  composed  of  a  large  number  of  bent 
tubes  which  will  expose  a  large  area  of  surface  to  the  cooling  influence 
of  the  air  draught  forced  through  the  radiator  either  by  the  forward 
movement  of  the  vehicle  or  by  some  type  of  fan.  The  cellular  and 
flat  tube  types  have  almost  entirely  displaced  the  flange  tube  radiators 
which  were  formerly  popular  because  they  cool  the  water  more 
effectively,  and  may  be  made  lighter  than  the  tubular  radiator  could 
be  for  engines  of  the  same  capacity. 


Filler  Cap. 


Cooling  Fan. 

Centrifugal  Pump. 


Fig.  221. — Elements  of  Typical  Cooling  Group,  Defining  Construction  of  Cen- 
trifugal Pump,  Cooling  Fan  and  Cellular  Cooler. 

The  water  is  drawn  from  the  lower  header  of  the  radiator  by  the 
pump  and  is  forced  through  a  manifold  to  the  lower  portion  of  the 
water  jackets  of  the  cylinder.  It  becomes  heated  as  it  passes  around 
the  cylinder  walls  and  combustion  chambers  and  the  hot  water  passes 
out  of  the  top  of  the  water  jacket  to  the  upper  portion  of  the  radiator. 
Here-  it  is  divided  in  thin  streams  and  directed  against  comparatively 
cool  metal  which  abstracts  the  heat  from  the  water.  As  it  becomes 
cooler  it  falls  to  the  bottom  of  the  radiator  because  its  weight  increases 
as  the  temperature  becomes  lower.  By  the  time  it  reaches  the  lower 
tank  of  the  radiator  it  has  been  cooled  sufficiently  so  that  it  may  be 
again  passed  around  the  cylinders  of  the  motor.  In  some  cooling 
systems,  especially  those  employing  cellular  type  coolers,  it  is  neces- 
sary to  use  a  cooling  fan  to  draw  currents  of  air  through  the  inter- 
stices of  the  cooler. 


392 


The  Modern  Gasoline  Automobile 


The  pumps  used  differ  in  design.  The  form  shown  at  Fig.  221 
and  at  Fig.  222,  A,  is  known  as  the  "  centrifugal  type "  because  a 
rotary  impeller  of  paddle-wheel  form  throws  water  which  it  receives 
at  a  central  point  toward  the  outside  and  thus  causes  it  to  maintain 
a  definite  rate  of  circulation.  The  pump  may  be  a  separate  appliance, 


Fan  Blade. 


Water  Space. 
Water  Inlet. 


Water  Inlet. 


Stuffing  Box; 

Water  Impeller 
i  Ball  Bearing. 

A 


B  ,  Water  Outlet. 


Fig.  222. — Two  Forms  of  Water-Circulating  Pumps  Representing  Current  Prac- 
tice. A — Cooling  Fan  and  Water  Pump  Driven  from  Common  Source  by 
Single  Belt;  Pump  Impeller  Placed  Directly  in  Water  Jacket.  B— Gear 
Circulating  Pump. 

as  shown  at  Figs.  220  and  221,  or  it  may  be  incorporated  in  part  of 
the  water  jacket,  as  depicted  at  Fig.  222,  A.  The  centrifugal  pump 
is  not  as  positive  as  the  gear  form  shown  at  Fig.  222,  B,  and  some 
manufacturers  prefer  the  latter  because  of  the  positive  pumping 
features.  They  are  very  simple  in  form,  consisting  of  a  suitable  cast 
JK>dy  in  which  a  pair  of  spur  pinions  having  large  teeth  are  carried. 
One  of  these  gears  is  driven  by  suitable  means  and  as  it  turns  the 
other  member  they  maintain  a  flow  of  water  through  the  central 
portion  of  the  pump.  The  pump  should  always  be  installed  in  series 
with  the  water  pipe  which  conveys  the  cool  liquid  from  the  lower 
compartment  of  the  radiator  to  the  coolest  portion  of  the  water  jacket. 
Water  Circulation  by  Natural  System. — Some  engineers  contend 
that  the  rapid  water  circulation  obtained  by  using  a  pump  may  cool 
the  cylinders  too  much,  and  that  the  temperature  of  the  engine  may 
be  reduced  so  much  that  the  efficiency  will  be  lessened.  For  this 
reason  there  as  a  growing  tendency  to  use  the  natural  method  of  water 
circulation  as  the  cooling  liquid  is  supplied  to  the  cylinder  jackets 


The  Modern  Gasoline  Automobile 


393 


just  below  the  boiling  point,  and  the  water  issues  from  the  jacket  at 
the  top  of  the  cylinder  after  it  has  absorbed  sufficient  heat  to  raise 
it  just  about  to  the  boiling  point. 

The  cooling  system  depicted  at  Fig.  223  is  one  that  has  demon- 
strated its  worth  conclusively  in  practice  and  is  somewhat  simpler 
than  the  forms  in  wrhich  a  pump  is  used  to  maintain  circulation. 
With  this  method,  the  fact  that  water  becomes  lighter  as  its  tempera- 
ture becomes  higher  is  taken  advantage  of  in  securing  circulation 
around  the  cylinders.  The  top  of  the  water  jacket  of  the  individu- 
ally cast  cylinders  is  attached  to  the  center  of  the  radiator,  while 


"Radiator 


/Radiator 


Fig.  223. — Water-Cooling  Group  Used  on  Maxwell  Automobiles  in  which  Water 
Circulation  is  Maintained  by  Natural  Means.  A — Side  View  of  Power 
Plant  Showing  Application  of  Piping.  B — Plan  View  Outlining  Disposition 
of  Parts. 

the  pipe  leading  from  the  bottom  of  that  member  is  connected  to  a 
manifold  which  supplies  cool  water  to  the  bottom  of  the  cylinder 
jackets.  With  such  a  system  it  is  imperative  that  the  radiator  be 
carried  at  such  a  height  that  the  cool  water  will  flow  to  the  water 
spaces  around  the  cylinder  by  gravity. 

As  the  water  becomes  heated  by  contact  with  the  hot  cylinder  and 
combustion-chamber  walls  it  rises  to  the  top  of  the  water  jackets,  flows 
to  the  cooler,  where  enough  of  the  heat  is  absorbed  to  cause  it  to 
become  sensibly  greater  in  weight.  As  the  water  becomes  cooler,  it 
falls  to  the  bottom  of  the  radiator  and  it  is  again  supplied  to  the 


394 


The  Modern  Gasoline  Automobile 


water  jacket.  The  circulation  is  entirely  automatic  and  continues 
as  long  as  there  is  a  difference  in  temperature  between  the  liquid  in 
the  water  spaces  of  the  engine  and  that  in  the  cooler.  The  circula- 
tion, becomes  brisker  as  the  engine  becomes  hotter  and  thus  the  tem- 
perature of  the  cylinders  is  kept  more  nearly  to  a  fixed  point.  With 
the  thermosyphon  system  -the  cooling  liquid  is  nearly  always  at  its 
boiling  point,  whereas  if  the  circulation  is  maintained  by  a  pump 
the  engine  will  become  cooler  at  high  speed  and  will  heat  up  more 
at  low  speed. 

There  are  two  methods  of  applying  the  thermosyphon  system  in 
a  practical  manner,  the  most  common  being  that  outlined  at  Fig.  223. 
Here  the  radiator  is  carried  at  the  front  end  of  the  car  and  a  fan 


Radiator 


Air  Space 


Underpan 


Flywheel  Fan 


Air  Outlet 


Fig.  224. — Renault  Thermosyphon  System,  in  which  Radiator  is  Placed  in  Back 
of  Engine  Instead  of  in  Front,  as  is  Conventional  Practice.  A — Showing 
Method  of  Utilizing  Fan  Fly  Wheel  to  Insure  Air  Circulation  Through  Radia- 
tor. B— Plan  View  Depicting  Flow  of  Air  Currents  Through  Cooler. 

driven  from  the  crank  shaft  by  belt  connection  is  used  to  draw  the 
air  through  the  radiator.  The  other  system,  which  is  illustrated  at 
Fig.  224,  is  one  that  was  introduced  on  the  Renault  automobile  In 
this  the  radiator  is  mounted  just  forward  of  the  dashboard  instead 
of  at  the  front  of  the  frame.  The  air  draught  through  the  radiator  is 
produced  by  the  suction  effect  of  a  fan  member  which  is  incorporated 
with  the  fly  wheel. 

When  a  radiator  is  mounted  at  the  front  end  of  a  frame,  it  is  one 
of  the  most  vulnerable  portions  of  the  motor-car  mechanism,  and  as 


The  Modern  Gasoline  Automobile 


395 


they  are  delicately  constructed  they  may  be  easily  damaged  in  collis- 
When  installed  as  shown  at  Fig.  224,  they  are  protected  by  the 


ion. 


heavier  construction  of  the  cylinders  and  other  portions  of  the  motor 
and  are  not  liable  to  be  damaged.  Then  again,  as  the  fan  is  incorpo- 
rated with  the  fly  wheel  and  driven  directly  by  the  crank  shaft  of  the 
motor,  there  is  no  possibility  of  failure  of  this  member,  such  as  might 
be  possible  when  it  is  driven  by  a  belt  connection  from  the  front  end 
of  the  engine. 

With  the  thermosyphon  or  natural  system  of  cooling  more  water 
must  be  carried  than  with  the  pump  maintained  circulation  methods. 


Water  Outlet 


Water  Inlet 


Fig.  225. — Showing  Large  Water  Manifolds  Designed  to  Secure  Positive  Circu- 
lation by  Thermosyphon  or  Natural  Methods. 

The  water  spaces  around  the  cylinders  should  be  larger,  the  inlet  and 
discharge  water  manifolds  should  have  greater  capacity,  and  be  free 
from  sharp  corners  which  might  impede  the  flow.  The  radiator  must 
also  carry  more  water  than  the  form  used  in  connection  with  the 
pump  because  of  the  brisker  pump  circulation  which  maintains  the 


396 


The  Modern  Gasoline  Automobile 


-Fan  Blade, 


Grease  Cup. 


engine  temperature  to  a  lower  point.  The  large  piping  which  expe- 
rience has  shown  necessary  is  clearly  shown  in  views  previously  de- 
scribed and  in  Fig.  225. 

The  form  of  fan  which  is  gen- 
erally placed  behind  the  radiator 
with  either  system  of  water  cool- 
ing, and  which  is  often  used  in  the 
simple  air-cooling  systems  as  well, 
is  shown  in  part  section  at  Fig. 
226.  The  hub  is  usually  a  cast- 
aluminum  member  which  has  a 
series  of  projecting  spokes  to 
which  the  fan  blades  are  riveted. 
The  blades  are  inclined  at  the 
proper  angle  to  draw  air  through 
the  radiator  and  force  it  to  the  rear 
of  the  motor  compartment.  As  a 
fan  requires  but  little  power,  they 
are  usually  driven  by  small  leather 
belts  and  as  they  operate  at  speeds 
two  or  three  hundred  per  cent 
greater  than  that  of  the  motor- 
crank  shaft  they  are  mounted  on 
ball  bearings  in  order  that  they 
may  turn  with  as  little  friction 
as  possible.  The  fan  spindle  is 
usually  supported  by  some  form  of 
movable  bracket  which  can  be  ad- 
justed so  that  the  fan  belt  may  be 
maintained  at  a  constant  degree 
of  tension. 

Direct  Air-Cooling  Methods. — 


Swing  Supported 
for  Fan  Belt 
Adjustment. 


Fig.  226.— Typical  Bail-Bearing,  Hub- 
Cooling  Fan  Designed  to  Create 
Air  Draught  Through  Radiator  and 
Around  Cylinders  of  Motor-Car 
Power  Plant. 


The  earliest  known  method  of  cool- 
ing the  cylinder  of  gas  engines  was 
by  means  of  a  current  of  air  passed 
through  *a  jacket  which  confined  it  close  to  the  cylinder  walls  and 
was  used  by  Daimler  on  his  first  gas  engine.  The  gasoline  engine 


The  Modern  Gasoline  Automobile 


397 


of  that  time  was  not  as  efficient  as  the  later  form,  and  other  condi- 
tions which  materialized  made  it  desirable  to  cool  the  engine  by  water. 
Even  as  gasoline  engines  became  more  and  more  perfected  there  has 
always  existed  a  prejudice  against  air  cooling,  though  many  forms  of 
engines  have  been  used,  both  in  stationary  and  automobile  applications 
where  the  air-cooling  method  has  proven  to  be  very  practical. 

The  simplest  system  of  air  cooling  is  that  in  which  .the  cylinders 
are  provided  with  a  series  of  flanges  which  increase  the  effective  radi- 
ating surface  of  the  cylinder  and  'directing  an  air  current  from  a 
fan  against  the  flanges  to  absorb  the  heat.  This  increase  in  the  avail- 


.Cooling  Fein 


Flanged 
Cylinders 


Fig.  227. — Air-Cooling  System  Employed  on  Cameron  Motors  Depends  Upon 
Air  Draught  from  Fan  to  Circulate  Around  Flanges  on  Cylinders  and  Absorb 
Excess  Heat 

able  radiating  surface  of  an  air-cooled  cylinder  is  necessary  because 
air  does  not  absorb  heat  as  readily  as  water  and  therefore  more  sur- 
face must  be  provided  that  the  excess  heat  be  absorbed  sufficiently  fast 
to  prevent  distortion  of  the  cylinders.  Air-cooling  systems  are  based 
on  a  law  formulated  by  Newton,  which  is :  "  The  rate  for  cooling  for 


398  The  Modern  Gasoline  Automobile 

a  body  in  a  uniform  current  of  air  is  directly  proportional  to  the 
speed  of  the  air  current  and  the  amount  of  radiating  surface  exposed 
to  the  cooling  effect."  A  simple  four-cylinder  power  plant  in  which 
cooling  is  obtained  by  air  blast  against  the  flanges  of  the  cylinders  is 
depicted  at  Fig.  227,  and  views  of  a  cylinder  and  detachable  head 
construction  also  adapted  to  be  cooled  by  air  are  shown  at  Fig.  228. 


'Cooling  Flanges 

Piston  Rings 


r,,,  ,  _  J\ 
I  %-y"te  :*   Connecting  Rod 


Detachable  Head 


Fig.  228. — Parts  of  Air-Cooled  Cylinder  Showing  Method  of  Seating  Valves 
Directly  in  Detachable  Cylinder  Head,  and  Large  Flanges  on  Both  Cylinder 
and  Head  Member  to  Largely  Increase  Effective  Radiating  Surface. 

There  are  certain  considerations  which  must  be  taken  into  ac- 
count in  designing  an  air-cooled  engine,  which  are  often  overlooked 
in  those  forms  cooled  by  water.  Large  valves  must  be  provided  to 
insure  rapid  expulsion  of  the  flaming  exhaust  gas  and  also  to  admit 
promptly  the  fresh  cool  mixture  from  the  carburetor.  The  valves  of 
air-cooled  engines  are  usually  placed  in  the  cylinder  head,  as  shown  at 
Figs.  227  and  228,  in  order  to  eliminate  any  pockets  or  sharp  pas- 
sages which  would  impede  the  flow  of  gas  or  retain  some  of  the 
products  of  combustion  and  their  heat.  When  high  power  is  desired 
multiple-cylinder  engines  should  be  used,  as  there  is  a  certain  limit  to 
the  size  of  a  successful  air-cooled  cylinder.  Much  better  results  are 
secured  from  those  having  small  cubical  contents  because  the  heat 
from  small  quantities  of  gas  will  be  more  quickly  carried  off  than 
from  greater  amounts.  All  successful  engines  of  the  automobile  type 
which  have  been  air  cooled  have  been  of  the  multiple-cylinder  type 
and  the  use  of  single  cylinders  is  confined  to  power  plants  of 
than  five  horse  power  such  as  used  in  motorcycle  construction, 


The  Modern  Gasoline  Automobile  399 

An  air-cooled  engine  must  be  placed  in  a  chassis  in  such  a  way 
that  there  will  be  a  positive  circulation  of  air  around  it  all  the 
time  that  it  is  in  operation.  This  air  current  may  be  produced  by 
a  fan  at  the  front  end  of  the  motor,  by  natural  draught  when  a  car 
is  in  motion,  or  by  a  suction  or  blower  fan  in  the  fly  wheel.  Greater 
care  is  required  in  lubrication  of  the  air-cooled  cylinders  and  only  the 
best  quality  of  oil  should  be  used  to  insure  satisfactory  oiling. 

The  combustion  chambers  must  be  proportioned  so  that  distribu- 
tion of  metal  is  as  uniform  as  possible  in  order  to  prevent  uneven 
expansion  during  increase  in  temperature  and  uneven  contraction 
when  the  cylinder  is  cooled.  It  is  essential  that  the  inside  walls  of 
the  combustion  chamber  be  as  smooth  as  possible  because  any  sharp 
angle  or  projection  may  absorb  sufficient  heat  to  remain  incandescent 
and  cause  trouble  by  igniting  the  mixture  before  the  proper  time. 
The  best  grades  of  cast  iron  should  be  used  in  the  cylinder  and  piston 
and  the  machine  work  must  be  done  very  accurately  so  the  piston  will 
operate  with  minimum  friction  in  the  cylinder. 

Utility  of  Auxiliary  Exhaust  Valves. — As  an  example  of  the  care 
taken  in  disposing  of  the  exhaust  gases  in  order  to  obtain  practical 
air  cooling  the  illustration  at  Fig.  229  is  presented.  This  is  a  sec- 
tion through  the  bottom  of  one  of  the  Franklin  power  plants  and 
shows  the  auxiliary  exhaust  valve  whicn  is  furnished  as  an  adjunct 
to  the  regular  member  in  the  cylinder  head.  The  auxiliary  exhaust 
valve  opens  just  as  soon  as  the  full  force  of  the  explosion  has  been 
spent  and  the  greater  portion,  or  70%,  of  the  flaming  gases  is  dis- 
charged through  the  port  in  the  bottom  of  the  cylinder.  But  30% 
of  the  exhaust  gases  remain  to  be  discharged  through  the  regular 
exhaust  member  in  the  cylinder  head  and  this  will  not  heat  the  walls 
of  the  cylinder  nearly  as  much  as  the  larger  quantity  of  hot  gas  would. 
That  the  auxiliary  exhaust  valve  is  of  considerable  value  is  conceded 
by  many  engineers  unless  exceptional  care  is  taken  in  the  method  of 
cooling  employed.  The  earlier  Franklin  engine,  which  used  the  auxil- 
iary exhaust  valves,  was  cooled  by  an  air  blast  from  a  fan  at  the 
front  end  which  was  directed  against  flanges  applied  to  the  cylinders, 
but  on  later  models  the  auxiliary  valve  has  been  dispensed  with  be- 
cause the  more  positive  system  of  cooling  provided  makes  its  use 
unnecessary. 


400 


The  Modern  Gasoline  Automobile 


One  of  the  important  considerations  in  connection  with  air  cool- 
ing is  that  the  air  blast  be  confined  as  close  to  the  cylinders  as  possible 
and  a  more  energetic  flow  of  air  is  needed  than  with  water-cooling 


Cooling  Flanges. 


Auxiliary 
Exhaust  Valve. 


Fig.  229. — Depicting  Section  Through  Power  Section  of  One  Type  of  Franklin 
Engine,  Showing  Application  of  Auxiliary  Exhaust  Valve  to  Relieve  Cylinder 
of  Flaming  Gases  at  End  of  Power  Stroke. 

systems.  The  form  of  fan  shown  at  Fig.  226  and  at  Fig.  230,  A,  is 
considered  entirely  adequate  for  water-cooled  engines,  but  engineers 
who  favor  air  cooling  at  the  present  time  use  blower  forms  _3uch  as 


The  Modern  Gasoline  Automobile 


401 


shown  at  Fig.  230.,  B,  which  will  furnish  larger  quantities  of  air  than 
the  simple  fan  would  and  which  also  direct  it  to  the  cylinders  in  a 
positive  manner  by  enclosing  them  in  air  jackets  which  are  attached 
to  a  manifold  member  to  which  the  discharge  opening  of  the  blower 
is  coupled. 

The  discussion  of  air  cooling  so  far  has  considered  only  the  adapta- 
bility to  the  four-stroke  motor  and  many  believe  that  it  is  not  possible 


Fan. 


Air  Outlet. 


Blower  Blades. 


Driving 
Gears. 


Crank-shaf 
Gear. 


Air  Inlet. 


Fig.  230. — Two  Forms  of  Positive  Air  Fans  Used  in  Automobile-Cooling  Systems. 
A — Gear-Driven,  Three-Blade  Fan  Utilized  to  Draw  Air  Through  Winton 
Radiator.  B — Blower  Member  Used  on  Kelly  Air-Jacketed  Cylinder 
Motor. 

to  cool  two-cycle  engines  by  this  method  because  the  great  heat  gen- 
erated in  engines  of  this  type  is  thought  to  make  the  use  of  water 
cooling  imperative.  As  the  two-cycle  motor  has  an  explosion  in 
each  cylinder,  every  revolution  of  the  crank  shaft,  and  has  no  strokes 
devoted  exclusively  to  scavenging,  it  is  true  the  cylinder  walls  will 
heat  up  more.  Several  forms  of  two-cycle  engines  have  been  evolved, 
however,  in  which  positive  cooling  has  been  obtained  by  providing  the 
cylinders  with  cooling  ribs.  One  of  these,  which  is  used  in  the  Chase 
light  truck,  is  depicted  in  section  at  Fig.  231.  It  will  be  noted  that 


402 


The  Modern  Gasoline  Automobile 


Exhaust 


the  exhaust  ports  are  large  and  that  the  transfer  port  for  the  passage 
of  the  gas  from  the  crank  case  to  the  cylinder  is  proportioned  so  that 

it  will  have  a  minimum  resistance 
to  the  gas  flow. 

Two  engines  of  modern  devel- 
opment which  utilize  positive  air- 
cooling  methods  are  shown  at  Figs. 
232  and  233.  The  system  of  cool- 
ing is  practically  the  same  in  both 
instances,  except  in  the  methods 
employed  of  creating  the  air  blast. 
In  the  Franklin  system  the  cyl- 
inders are  provided  with  vertical 
ribs,  or  flanges,  and  are  encased 
by  jackets  which  form  part  of 
a  sheet-metal  casing  that  covers 
the  entire  lower  portion  of  the 
power  plant.  The  fly  wheel  is 
provided  with  a  series  of  curved 
blower  blades  and  as  it  turns  it 
creates  a  partial  vacuum  in  the 
compartment  formed  by  the  mo- 
tor-base casing  and  the  air-tight 
underpan.  The  strong  suction 
created  draws  air  in  from  the 
front  end  of  the  bonnet  and  down 
through  the  cylinder  jackets.  The 
air  currents  pass  over  the  flanges  at  high  velocity  and  as  there  is 
a  large  amount  of  exposed  surface  the. excess  heat  is  promptly  dis- 
posed of  and  absorbed  by  the  air  passing  around  the  cylinders  which 
is  ejected  from  the  motor-base  compartment  by  the  action  of  the 
blower  fly  wheel.  As  the  fan  is  part  of  the  balance  member  and  is 
driven  direct  from  the  engine  crank  shaft  there  can  be  no  failure  of 
the  driving  means  and  a  positive  air  draught  must  be  induced  around 
the  cylinders  as  soon  as  the  motor  is  started.  The  velocity  of  the  air 
currents  increase  directly  as  the  motor  speed  augments,  and  positive 
cooling  is  obtained  under  all  conditions. 


Fig.  231. — Sectional  View  of  Chase 
Two-Cycle  Engine,  a  Two-Stroke 
Form  Successfully  Cooled  by  Air 
Flanges  Cast  Integral  with  Cylinder. 


The  Modern  Gasoline  Automobile 


403 


In  the  Frayer-Miller  engine  which  is  used  in  the  Kelly  trucks,  the 
method  of  cooling  is  different  in  detail  but  practically  the  same  in 
principle  as  that  previously  described.  An  air  blower  is  mounted  at 
the  front  end  of  the  motor  and  the  strong  current  of  air  it  produces 
is  conveyed  to  an  air  pipe  at  the  top  of  the  cylinders,  to  which  the 
jackets  surrounding  them  are  attached.  The  cylinder  heads  are  pro- 
vided with  a  series  of  vertical  flanges,  but  the  cylinder-wall  area  is 


Cylinder  Jacket. 


Air  Inlet. 


Fig.  232. — Positive  Cooling  Method  Used  on  Franklin  Automobiles  in  which  Air 
Currents  are  Drawn  Through  Cylinder  Jackets  by  Fly-wheel  Fan  Suction. 

increased  by  using  a  large  number  of  spines  which  are  cast  integral 
with  the  cylinder.  The  air  blower  forces  a  blast  of  air  into  the  air 
pipe  above  the  cylinders  at  considerable  pressure,  and  the  only  way 
it  can  escape  is  by  passing  around  the  heated  portion  of  the  cylinder 
before  it  is  discharged  through  the  bottom  of  the  air  jacket.  As  the 
blower  speed  increases  with  engine  speed  the  value  of  the  air  current 
becomes  greater  when  an  augmented  cooling  effect  is  desired. 

Among  the  advantages  stated  for  air  cooling  the  greatest  is  the 
elimination  of  cooling  water,  which  is  a  factor  of  some  moment.  In 
the  temperate  zone,  where  the  majority  of  automobiles  are  used,  the 
weather  conditions  change  in  a  very  few  months  from  the  warm 


404 


The  Modern  Gasoline  Automobile 


summer  to  the  extreme  cold  winter,  and  when  water-cooled  systems 
are  employed  it  is  necessary  to  add  some  chemical  substance  to  the 
water  to  prevent  it  from  freezing.  The  substances  commonly  em- 
ployed are  glycerine,  wood  alcohol,  or  a  saturated  solution  of  calcium 
chloride.  Alcohol  has  the  disadvantage  in  that  it  vaporizes  readily 
and  must  be  often  renewed.  Glycerine  affects  the  rubber  hose,  while 
the  calcium  chloride  solution  crystallizes  and  deposits  salt  in  the 
radiator  and  water  pipes. 

Obviously  the  elimination  of  water  and  the  use  of  air  cooling  will 
provide  a  system  that  will  be  fully  as  effective  during  the  extreme 


Air  Pipe 


Fig.  233.— Air- Jacketed  Prayer-Miller  Engine  Used  in  Kelly  Trucks  Cooled  by 
Air  Currents  Directed  Over  Cylinders  by  Positive  Air-Blower  System. 

cold  weather  as  it  is  during  the  more  favorable  summer  season.  It 
would  seem  that  air-cooling  methods  could  be  applied  to  advantage  in 
commercial  vehicle  power  plants  which  must  be  capable  of  efficient 
service  under  widely  varying  conditions.  One  of  the  disadvantages 
of  an  air-cooling  method  as  stated  by  those  who  do  not  favor  this 
system  is  that  engines  cooled  by  air  cannot  be  operated  for  extended 
periods  under  overloads  or  at  very  high  speed  without  heating  up  to 


The  Modern  Gasoline  Automobile  405 

such  a  point  that  premature  ignition  of  the  charge  may  result.  The 
water-cooling  systems,  at  the  other  hand,  maintain  the  temperature  of 
the  engine  more  nearly  constant  than  is  possible  with  an  air-cooled 
motor,  and  an  engine  cooled  by  water  can  be  operated  under  condi- 
tions of  inferior  lubrication  or  poor  mixture  adjustment  that  would 
seriously  interfere  with  proper  and  efficient  cooling  by  air. 

Air-cooled  motors,  as  a  rule,  use  less  fuel  than  water-cooled  en- 
gines because  the  higher  temperature  of  the  cylinder  does  not  permit 
of  a  full  charge  of  gas  being  inspired  on  the  intake  stroke.  As  special 
care  is  needed  in  driving  an  air-cooled  car  to  obtain  satisfactory  re- 
sults and  because  of  the  greater  difficulty  which  obtains  in  providing 
proper  lubrication  and  fuel  mixtures  which  will  not  produce  undue 
heating,  the  air-cooled  system  has  but  few  adherents  at  the  present 
time  and  practically  all  automobiles,  with  but  very  few  exceptions, 
are  provided  with  water-cooled  power  plants. 


CHAPTER    VIII 

Utility  of  Clutches  and  Gearsets  Defined— Why  These  Vital  Components  of 
the  Transmission  System  Are  Needed  on  Gasoline  Motor-driven  Vehicles 
— Conventional  Forms  of  Cone  Clutch  and  their  Practical  Application — • 
Characteristics  of  Three-  and  Five-plate  and  Multiple-disk  Clutches — 
Function  of  Gearset — Types  of  Speed  Changing  Mechanism— The  Fric- 
tion Transmission — Planetary  and  Individual  Clutch  Types— Progressive 
and  Selective  Sliding  Gearsets — Typical  Speed  Changing  Mechanisms  Out- 
lined,, 

ONE  of  the  important  functions  making  for  efficient  operation 
of  the  gasoline  motor  car  is  the  method  of  power  transmission  em- 
ployed. While  power  plant  efficiency  is  an  important  factor  and  one 
that  should  be  conserved  to  the  utmost,  it  is  well  to  remember  that 
the  actual  power  of  the  car  is  not  the  rated  power  of  the  engine  but 
the  amount  of  energy  exerted  at  the  point  of  contact  between  the 
traction  members  and  the  ground.  A  60  H.  P.  car  in  which  there 
is  a  30%  loss  in  power  transmission  is  not  as  efficient  as  a  vehicle  of 
but  45  H.  P.  which  delivers  the  power  to  the  rear  wheels  with 
but  10%  loss.  Under  the  conditions  stated  the  rear  wheels  of  the 
lower-powered  car  would  actually  receive  more  useful  effort  than  the 
driving  members  of  the  high-powered  vehicle,  and  the  energy  is 
supplied  with  less  stress  on  the  various  parts  and  with  a  lower  fuel 
consumption. 

The  attention  of  mechanical  engineers  had  been  directed  to  the 
efficient  transmission  of  power  long  before  the  motor  car  was  com- 
mercially practical.  As  a  result  many  ingenious  systems  which 
had  been  applied  in  standard  mechanical  work  and  for  driving  the 
machine  tools  of  manufacturing  establishments  have  been  readapted 
for  use  in  motor-car  propulsion.  One  who  has  studied  the  subject 
can  easily  trace  the  evolution  from  the  crude  forms  of  a  decade  ago 
to  the  perfected  types  used  in  modern  automobiles.  The  problem  of 
power  transmission  in  motor  cars  was  one  that  was  not  easily  solved, 

406 


407 


408  The  Modern  Gasoline  Automobile 

and  much  experimenting  was  necessary  before  the  perfected  forms  of 
the  present  day  were  evolved. 

A  typical  power-transmission  group  such  as  employed  in  the 
modern  gasoline  automobile  is  depicted  in  Fig.  234.  In  this  the 
power  is  applied  to  the  crank  shaft  of  the  motor  and  from  thence  it 
is  delivered  to  the  motor  fly  wheel  which  forms  the  female  member 
of  a  friction  clutch.  The  male  member  .of  the  clutch  is  coupled  to 
the  change-speed  gearing  and  this  in  turn  is  joined  to  the  driving 
pinion  in  the  rear  axle  by  a  length  of  shaft.  The  driving  pinion 
delivers  its  power  to  a  bevel-driving  gear  which  is  carried  by  the 
differential  casing  in  the  rear  axle  housing.  From  the  differential 
gear  independent  shafts  or  axles  drive  the  rear  wheel  hubs. 

The  function  of  the  clutch  is  to  permit  the  engine  to  be  run  in- 
dependently of  the  transmission  gearing  when  desired.  The  engine 
can  drive  the  car  only  when  one  of  the  sets  of  gears  in  the  gearset 
and  the  clutch  are  engaged  simultaneously.  For  example,  if  the 
clutch  is  out  or  released,  even  if  the  gears  were  in  mesh  in  the 
change-speed  device,  the  rear  wheels  would  not  be  turned  until  the 
clutch  cone  was  allowed  to  engage  the  female  member  formed  in  the 
fly-wheel  rim.  At  the  other  hand,  when  the  parts  are  as  shown  with 
the  clutch  in  engagement  and  the  speed  gears  out  of  mesh  the  engine 
can  still  be  revolved  without  turning  the  rear  wheels. 

Why  Clutch  Is  Necessary. — In  order  to  secure  a  better  understand- 
ing of  the  general  requirements  of  clutching  devices  it  will  be  well 
to  consider  the  conditions  which  make  their  use  imperative  when 
a  motor  car  is  propelled  by  a  hydrocarbon  motor.  If  a  steam  engine 
or  an  electric  motor  are  installed  as  prime  movers  it  is  not  necessary 
to  include  any  clutching  device  or  gearset  between  them  and  the 
driving  wheels,  and  these  members  may  be  driven  directly  from 
the  power  plant  if  desired.  With  either  of  the  forms  mentioned 
the  power  is  obtained  from  a  separate  source  which  may  be  uncoupled 
from  the  motor  by  the  simple  movement  of  a  throttle  valve  or  switch 
lever.  Steam  and  electric  motors  are  also  capable  of  delivering  power 
in  excess  of  their  rating  and  are  more  flexible  than  internal  combus- 
tion power  plants. 

If  stean^  is  the  motive  agent  it  is  generated  and  contained  in  a 
special  device  known  as  a  boiler,  and  the  amount  of  power  delivered 


The  Modern  Gasoline  Automobile  409 

by  the  engine  to  which  the  boiler  is  connected  will  vary  with  the 
amount  of  steam  admitted  and  its  pressure.  If  the  steam  supply 
is  interrupted  entirely  the  engine  and  the  car  which  it  drives  are 
brought  to  a  stop.  When  it  is  desired  to  start  again  a  simple  move- 
ment of  the  throttle-valve  lever  will  permit  the  steam  to  flow  from 
the  boiler  to  the  engine  cylinders  again  and  the  vehicle  is  easily  set 
in  motion.  If  it  is  desired  to  reverse  the  car  the  steam  flow  is  re- 
versed by  a  simple  mechanical  movement  and  the  engine  will  run 
in  the  opposite  direction  to  that  which  obtains  when  the  car  is  driven 
in  a  forward  direction. 

If  an  electric  motor  drives  a  vehicle  the  electrical  energy  is  se- 
cured from  a  group  of  storage  batteries.  When  these  are  fully 
charged  varying  amounts  of  electric  current  may  be  drawn  from 
them  and  allowed  to  flow  through  the  windings  of  the  field  or  arma- 
ture of  the  motor  and  different  ratios  of .  power  or  speed  obtained. 
The  vehicle  is  easily  started  by  completing  the  circuit  between  the 
motor  and  the  source  of  current  and  stopped  by  interrupting  the  sup- 
ply of  electrical  energy.  As  the  flow  of  electricity  can  be  reversed 
easily  by  a  switch  the  car  may  be  driven  backward  or  forward  at  will, 
and  as  the  speed  may  be  easily  varied  by  changing  the  value  of  the 
current  strength  there  is  no  need  of  spoed  changing  or  reversing  gears. 

When  a  gasoline  engine  is  fitted,,  conditions  are  radically  different 
than  with  either  a  steam  or  electric  power  plant.  The  power  devel- 
oped depends  upon  the  number  of  explosions  per  unit  time  and  the 
energy  augments  directly  as  the  number  of  explosions  and  revolutions 
of  the  crank  shaft  increase.  It  is  not  possible  to  start  a  gasoline 
engine  when  under  load  because  the  power  is  obtained  by  the  com- 
bustion of  fuel  directly  in  the  cylinders,  and  as  there  is  no  external 
source  of  power  to  draw  from  it  is  obvious  that  the  energy  derived 
depends  upon  the  rapidity  with  which  the  explosions  follow  each 
other.  It  has  been  demonstrated  that  a  certain  cycle  of  operation  is 
necessary  to  secure  gasoline-engine  action  and  it  is  imperative  that  the 
engine  revolves  freely  until  it  attains  sufficient  speed  to  supply  the 
torque  or  power  needed  to  overcome  the  resistance  that  tends  to 
prevent  motion  of  the  car  before  it  can  be  employed  in  driving  the 
vehicle. 

Then,  again,  it  is  very  desirable  that  the  vehicle  be  started  or 


410  The  Modern  Gasoline  Automobile 

stopped  independently  of  the  engine.  With  a  steam  or  electric  motor 
the  vehicle  may  be  started  just  as  soon  as  the  driving  power  is  ad- 
mitted to  the  prime  mover,  but  with  a  gasoline  engine  it  is  customary 
to  interpose  some  device  between  the  engine  and  driving  wheels 
which  make  it  possible  to  couple  the  engine  to  the  wheels  or  driving 
gearing  and  disconnect  it  at  will.  The  simplest  method  of  doing 
this  is  by  means  of  some  form  of  clutching  device  which  will  lock 
the  driving  shaft  to  the  crank  shaft  of  the  engine. 

Clutch  Forms  and  Their  Requirements. — Clutch  forms  that  have 
been  applied  to  automobile  propulsion  are  usually  of  the  frictional 
type,  though  some  have  been  devised  which  depend  upon  hydraulic, 
pneumatic,  or  magnetic  energy.  Those  which  utilize  the  driving 
properties  of  frictional  adhesion  are  most  common  and  have  proven 
to  be  the  most  satisfactory  in  practical  application.  The  most  impor- 
tant requirement  in  considering  clutch  forms  is  that  such  devices 
must  be  capable  of  transmitting  the  maximum  power  of  the  engines  to 
which  they  are  fitted  without  any  power  loss  due  to  slipping.  Such  a 
clutch  must  be  easy  to  operate  and  but  minimum  exertion  should  be 
required  of  the  operator.  When  the  clutch  takes  hold  the  engine 
power  should  be  transmitted  to  the  gearset  and  driving  means  in 
a  gradual  and  uniform  manner,  or  the  resulting  shock  may  seriously 
injure  the  mechanism.  When  released  it  is  imperative  that  the 
two  portions  of  the  clutch  disengage  positively  so  that  there  will  be 
no  continued  rotation  of  the  parts  after  the  clutch  is  disengaged. 

The  design  should  be  carefully  considered  with  a  view  of  provid- 
ing as  much  friction  surface  as  possible  to  prevent  excessive  slipping 
and  loss  of  power.  It  is  very  desirable  to  have  a  clutch  that  will  be 
absolutely  silent  whether  engaged  or  disengaged.  If  the  clutch  parts 
are  located  in  an  accessible  manner  it  may  be  easily  removed  for 
inspection,  cleaning,  or  repairs.  It  is  desirable  that  adjustment  be 
provided,  so  a  certain  amount  of  wear  can  be  compensated  for  with- 
out expensive  replacement.  A  simple,  substantial  design  with  but 
few  operating  parts  is  more  to  be  desired  than  a  more  complex  de- 
vice which  may  have  a  few  minor  advantages,  but  which  is  more  likely 
to  cause  trouble. 

The  friction  clutch  in  its  various  efficient  types  is  the  one  that 
more  nearly  realizes  the  requirements  of  the  ideal  clutch.  As  a  result 


The  Modern  Gasoline  Automobile  411 


this  form  is  now  universally  recognized  by  automobile  designers,  and 
all  standard  gasoline  automobiles  utilize  some  form  of  friction  clutch. 
These  devices  are  capable  of  transmitting  any  amount  of  power  if 
properly  proportioned,  and  permit  of  gradual  engagement  and  positive 
disconnection.  Most  friction  clutches  are  simple  in  form,  easily  un- 
derstood, and  may  be  kept  in  adjustment  and  repair  without  difficulty. 

How  Friction  Clutches  Transmit  Power. — To  illustrate  the  trans- 
mission of  power  by  the  frictional  adhesion  of  substances  with  each 
other  we  can  assume  a  simple  case  of  two  metal  disks  or  plates  in 
contact,  the  pressure  existing  between  the  surfaces  being  due  to  the 
weight  of  one  member  bearing  upon  the  other.  If  the  disks  are  not 
too  heavy,  it  will  be  found  comparatively  easy  to  turn  one  upon  the 
other,  but  if  weights  are  added  to  the  upper  member  a  more  decided 
resistance  will  be  felt  which  will  increase  directly  as  the  weight  on 
the  top  disk  and  consequently  the  pressure  between  the  disks  increases. 
It  may  be  possible  to  add  enough  weight  so  it  will  be  practically  im- 
possible to  move  one  plate  without  turning  the  other.  It  is  patent 
that  if  one  of  these  plates  was  mounted  rigidly  on  the  engine  shaft 
and  one  applied  to  the  transmission  shaft  so  that  it  had  a  certain7 
amount  of  axial  freedom  and  pressure  of  contact  was  maintained  by 
a  spring  instead  of  weights,  a  combination  capable  of  transmitting 
power  would  be  obtained.  The  spring  pressure  applied  to  one  disk 
would  force  it  against  the  other  and  one  shaft  could  not  turn  without 
producing  a  corresponding  movement  of  the  other, 

Materials  Employed  to  Increase  Frictional  Adhesion. — The  main 
object  of  engineers  in  designing  a  clutch  is  to  increase  the  amount  of 
friction  adhesion  existing  between  the  parts  as  much  as  possible.  The 
transmitting  efficiency  of  the  clutch  will  vary  with  the  coefficient  of 
friction  between  the  surfaces  and  the  more  the  friction  between  them 
the  more  suitable  the  clutch  will  be  for  transmitting  power.  A  metal 
usually  forms  one  frictional  surface  in  all  forms  of  clutches,  and  some 
types  have  been  designed  and  used  successfully  in  which  all  friction 
surfaces  are  metals. 

The  materials  of  a  metallic  nature  commonly  used  are  cast  iron, 
aluminum  and  bronze  castings,  and  sheet  steel  and  bronze,  usually 
in  the  form  of  thin-stamped  disks.  The  nonmetallic  frictional  ma- 
terials generally  used  are  leather,  asbestos  fabrics,  textile  beltings, 


412  The  Modern  Gasoline  Automobile 

and  cork.  Leather  is  the  best  lining  or  facing  for  clutches  where 
the  frictional  area  is  large.  When  used  it  must  be  kept  properly 
lubricated  and  soft,  as  if  it  becames  dry  it  will  engage  very  suddenly 
and  clutch  action  will  be  harsh.  At  the  other  hand,  care  must  be 
taken  not  to  supply  too  much  lubricant  or  the  coefficient  of  friction 
will  be  reduced  to  a  low  point  and  the  surfaces  will  slip.  Oak-tanned 
leather  is  generally  used  because  it  has  good  wearing  qualities,  is  a 
very  resilient  material,  and  possesses  a  very  satisfactory  degree  of 
frictional  adhesion  when  pressed  against  a  cast-iron  member.  As- 
bestos fabrics  are  being  applied  in  many  forms  of  dry  plate  clutches 
and  have  been  used  to  some  extent  in  facing  the  male  member  of  cone 
clutches.  These  are  not  as  elastic  as  leather  and  unless  some  auxil- 
iary-relieving member  is  employed  they  will  grip  suddenly  and  un- 
desirable harsh  clutch  action  obtain. 

When  cork  is  used  it  is  inserted  in  the  metal  surface  in  suitable 
holes  which  are  machined  to  receive  the  inserts.  Cork  possesses  pe- 
culiar qualities  which  make  it  very  suitable  for  use  in  a  clutch.  It 
has  perhaps  the  highest  coefficient  of  friction  of  any  of  the  materials 
employed,  is  not  materially  affected  by  either  excessive  lubrication 
or  lack  of  it,  and  possesses  very  desirable  wearing  qualities.  A  clutch 
fitted  with  cork  inserts  will  engage  gradually  and  power  will  be  trans- 
mitted to  the  rear  wheels  without  shock  or  jar.  It  is  the  lightest  and 
most  elastic  of  the  solids.  In  application  cork  must  be  used  as  an  in- 
sert, because  it  is  too  brittle  to  be  used  in  sheet  form  with  any  degree 
of  success. 

When  applied  to  a  clutch  the  cork  always  works  alone  at  low  or 
medium  pressures  and  at  high  pressures  the  other  surfaces  become 
engaged.  This  is  given  as  the  reason  for  the  excellent  wearing  qual- 
ities of  such  combination  surfaces,  and  when  corks  form  a  relatively 
large  proportion  of  one  of  the  contact  surfaces  they  prevent  cutting, 
no  matter  whether  there  is  lubricant  present  or  not.  Then  again, 
in  the  presence  of  a  lubricant,  which  would  obviously  cause  slippage 
between  plain  metallic  or  other  surfaces,  the  corks  so  largely  increase 
the  total  frictional  adhesion  that  slippage  is  almost  impossible. 

Opinions  vary  among  designers  regarding  the  most  suitable  ma- 
terials to  use,  though  the  selection  of  frictional  material  depends  in 
most  cases  upon  the  type  of  clutch  used.  The  large  majority  who 


The  Modern  Gasoline  Automobile 


413 


favor  the  cone  clutch  employ  a  leather  and  cast  iron  combination  and  in 
many  cases  cork  inserts  are  also  employed.  Metal  to  metal  surfaces 
are  the  rule  in  multiple  disk  or  plate  clutches  of  small  diameter, 
though  as  a  general  thing  when  a  lesser  number  of  plates  of  large 
diameter  are  used  cork  inserts  or  an  asbestos  fabric  facing  are  invari- 
ably provided  on  one  set  of  plates. 


Flange 
Integral 

with 
Crankshaft. 


Gearset  Driving 
Member. 


—    Ratention 
Nut. 

Ball  Thrust  Washer. 
Clutch  Spring. 


Fig.  235.— Sectional  View  of  Cone  Clutch  Having  Female  Member  Formed  In- 
tegral with  Fly- Wheel  Rim. 

Forms  of  Cone  Clutches  Outlined. — A  simple  and  efficient  form  of 
cone  clutch  is  shown  at  Fig.  235.  This  consists  of  three  main  parts, 
the  female  member,  which  is  machined  integral  with  the  fly  wheel,  a 


414  The  Modern  Gasoline  Automobile 

corresponding  male  member,  which  fits  into  it,  and  a  spring  to  main- 
tain contact  between  the  surfaces.  The  fly  wheel  is  attached  to  a  flange 
forged  integral  with  the  end  of  the  crank  shaft  by  suitable  screws. 
The  male  member  is  a  truncated  cone  of  metal  faced  with  leather. 
The  female  member  may  be  machined  integral  with  the  fly  wheel,  as 
shown  at  Fig.  235,  or  it  may  be  applied  to  the  fly-wheel  rim  by  means 
of  bolts,  as  outlined  at  Fig.  236. 

Experience  has  demonstrated  that  cast  iron  and  leather  make  a 
very  good  wearing  combination,  and  the  tendency  to  use  cork  inserts 
to  prevent  harsh  engagement  is  growing  at  the  present  time.  Plain 
metal-to-metal  surfaces  are  not  suitable  with  this  form  because  they 
would  grip  too  suddenly  and  would  soon  slip  if  there  was  a  thin 
film  of  oil  between  the  surfaces.  It  will  be  noted  that  in  either  case 
frictional  contact  between  the  clutch  cone  and  fly-wheel  rim  is  main- 
tained by  the  use  of  a  coil  spring  which  is  backed  by  a  ball-thrust 
bearing  in  order  to  relieve  the  operating  mechanism  of  any  torque 
strain  when  the  clutch  is  disengaged. 

In  the  cone  clutch  shown  at  Fig.  235,  the  male  member  is  carried 
by  a  hub  portion  to  which'  it  is  bolted,  concentric  with  an  annulus 
which  bears  on  the  crank-shaft  extension.  One  end  of  the  spring 
bears  against  the  closed  end  of  the  annulus  while  the  other  end  is 
held  by  the  ball-thrust  washer  and  nut  screwed  on  to  the  end  of  the 
crank  shaft.  The  spring  pressure  in  this  case  keeps  the  cone  seated 
by  pushing  it  directly  toward  the  crank  shaft.  When  it  is  desired 
to  release  the  clutch  the  operating  pedal  is  depressed  in  such  a  manner 
that  it  swings  on  the  fulcrum  point  and  moves  the  clutch  cone  and 
the  annulus  member  by  which  it  is  supported  back  so  the  clutch  cone 
is  pulled  away  from  the  fly  wheel  and  the  spring  compressed.  Some 
form  of  Oldham  coupling  or  sliding  joint  is  carried  by  the  gearset 
driving  member  and  is  attached  to  the  shaft  extending  from  the  go?ir 
case.  When  the  spring  pressure  forces  the  clutch  cone  into  engage- 
ment with  the  fly  wheel,  the  assembly  turns  as  a  unit  and  the  gear- 
set  is  driven  by  the  engine  crank  shaft  through  the  medium  of  the 
clutch  and  the  gearset  driving  member  which  is  attached  to  the 
clutch  cone.  When  the  cone  is  pulled  away  from  the  fly  wheel  the 
annulus  which  carries  the  gearset  driving  member  remains  stationary 
and  the  crank-shaft  extension  revolves  in  it. 


The  Modern  Gasoline  Automobile 


415 


The  clutch  outlined  at  Fig.  236  differs  from  that  previously  shown 
in  that  the  cone  is  inverted  and  the  spring  pressure  is  employed  to 


Retention  Bolt.         ,  Fly  wheel  Rim. 


Female  Member. 


Male  Cone. 


Fan  Blade 
Spoke. 


Crankshaf 


Fig.  236.— Cone  Clutch  Design  with  Female  Member  a  Separate  Casting  Bolted 

to  Fly- Wheel  Rim. 

push  the  cone  away  from  the  fly  wheel  to  engage  it.  The  cone  is 
carried  at  one  end  of  the  transmission  shaft  and  revolves  idly  when 
it  is  pushed  toward  the  fly  wheel  so  that  it  is  not  in  contact  Avith  the 


416 


The  Modern  Gasoline  Automobile 


female  member.  In  the  cone  clutch  previously  described  the  female 
member  was  machined  in  the  fly-wheel  rim.  In  that  outlined  at 
Fig.  236  the  female  member  is  a  separate  casting  bolted  to  the  fly- 
wheel rim. 

Typical  designs  of  clutch  cones  and  methods  of  fastening  the 
friction  facings  to  the  cone  castings  are  shown  at  Fig.  237.  In 
that  shown  at  A  a  combination  of  leather  facing  and  cork  inserts 
is  employed.  The  leather  is  secured  to  the  cast  aluminum  cone 
by  means  of  rivets  and  the  cork  inserts  are  forced  into  recesses 
cast  into  the  cone  member.  At  B  the  practical  method  of  retaining 
the  leather  facing  employed  on  White  automobiles  is  illustrated. 


Cork  Inserts 


Cone  Casting 
Leather 
Universal  Joint 

Leather 


Rivets 


Fig.  237. — Typical  Cone  Clutch  Male  Members,  Showing  Methods  of  Attaching 
Leather  Facing  to  Cone  Casting.  A — Pope-Hartford  Clutch  Cone  Faced 
with  Leather  and  Cork  Inserts.  B — White  Cone  Uses  Leather  Band  Held  in 
Place  by  T  Bolts. 

When  the  leather  facing  is  riveted  to  the  cone  rim  considerable  labor 
is  involved  in  removing  it  after  it  has  worn  to  such  a  point  that  re- 
placement is  necessary  because  the  large  number  of  rivets  must  be 
driven  out  before  the  leather  can  be  removed.  The  leather  band 
which  forms  the  friction  facing  of  the  cone  at  B  is  held  by  a  number 
of  T  head  bolts  which  pass  through  the  cone  rim  and  which  seat  into 
longitudinal  grooves  cast  into  the  periphery  of  the  cone  member. 
These  are'  of  sufficient  depth  to  prevent  the  heads  of  the  bolts  rub- 


The  Modern  Gasoline  Automobile 


417 


bing  against  the  female  member  of  the  clutch  and  only  the  leather 
facing  acts  as  a  driving  surface.  When  the  leather  becomes  worn 
it  is  a  comparatively  simple  matter  to  remove  the  T  bolts  and  put  a 
new  leather  band  in  place. 

On  some  cone  clutches  of  European  design  the  endeavor  has  been 
made  to  use  metal-to-metal  surfaces  by  housing  the  cone  in  an  oil- 


Clutch 
Release 
'Lever 


Crank 


Flywheel          Clutch  Corre 


/utch.  Cone 


Fig.  238.— Cone  Clutches  of  English  Design.  A— Metal-to-Metal  Surfaces  in 
Oil-Tight  Case.  B— Method  of  Holding  Parts  in  Contact  with  Adjustable 
Springs. 

tight  casing  so  that  it  worked  in  a  bath  of  lubricant.  The  lower  co- 
efficient of  friction  existing  between  lubricated  surfaces  is  compen- 
sated for  by  increasing  the  spring  pressure.  Such  a  clutch  is  shown 
in  section  at  Fig.  238,  A.  The  clutch  case  is  formed  of  two  members, 
one  of  these  being  the  fly  wheel,  which  is  attached  to  the  crank-shaft 
flange  by  bolts,  the  other  is  a  cast  casing,  which  is  bolted  to  the  fly- 
wheel rim  on  its  face.  The  clutch  cone  is  attached  to  a  sliding  shaft 
which  telescopes  on  to  the  projecting  end  of  the  crank-shaft  extension 
and  which  slides  through  an  oil-tight  bearing  carried  by  the  clutch 
case  which  is  bolted  to  the  fly-wheel  rim.  The  spring  thrust  is  taken 
at  one  end  by  the  clutch  casing  and  bears  against  a  ball-thrust 


418  The  Modern  Gasoline  Automobile 

washer  which  seats  against  the  flange  to  which  the  clutch  cone  is 
attached.  The  female  member  is  machined  in  the  fly  wheel  and  does 
not  differ  from  conventional  forms. 

Another  form  of  English  derivation  is  shown  at  Fig.  238,  B,  this 
differing  from  those  previously  described  only  in  the  method  of  ap- 
plying the  spring  pressure.  A  three-arm  spider  carries  three  studs 
spaced  at  120  degrees  which  also  pass  through  bosses  on  the  clutch 
cone.  The  spider  is  kept  in  place  by  a  ball-thrust  bearing  retained 
on  the  fly-wheel  hub  by  a  clamping  nut  screwed  on  a  thread  cut  at 
the  end  of  the  fly-wheel-retaining  member  which  serves  to  keep  the 
fly  wheel  in  place,  as  well  as  forming  a  backing  for  the  thrust  bear- 
ing. The  studs  which  project  through  the  clutch  cone  have  nuts 
threaded  on  the  outer  ends,  and  a  spring  is  mounted  outside  of  each 
clutch  cone  boss  in  such  a  way  that  it  presses  against  the  nut  on  the 
end  of  the  stud  and  presses  the  cone  into  engagement  with  the  fly 
wheel.  The  drive  is  interrupted  by  pulling  the  cone  out  of  engage- 
ment in  the  usual  manner. 

One  of  the  disadvantages  of  the  cone  clutch,  unless  it  is  exception- 
ally well  designed,  is  that  it  is  likely  to  engage  harshly  if  the  leather 
facing  becomes  charred  or  hard  from  any  other  cause.  When  cork 
inserts  are  used  in  connection  with  the  leather,  a  more  gradual  en- 
gagement is  secured,  even  when  the  leather  is  dry,  than  would  be 
possible  without  their  use.  Some  designers  have  sought  to  secure 
easy  engagement  by  using  a  number  of  auxiliary  friction  pads  at- 
tached to  the  cone  periphery,  while  others  have  been  satisfied  to  use 
springs  under  the  clutch  leather  which  would  raise  it  at  a  number  of 
points  around  the  periphery  of  the  clutch  cone.  The  object  of  this 
is  to  have  a  limited  area  of  the  leather  surface  engage  the  female 
member  before  the  full  spring  pressure  is  exerted  to  bring  the  entire 
frictional  surface  in  contact. 

The  clutch  shown  at  Fig.  239,  which  has  been  used  on  Columbia 
automobiles,  is  a  'conical  type  having  a  number  of  auxiliary  friction 
pads  extending  through  the  periphery  of  the  cone  and  projecting 
slightly  above  its  surface.  These  are  kept  in  place  by  auxiliary 
springs  of  the  coil  type.  When  the  clutch  cone,  is  first  engaged  these 
friction  shoes  will  engage  the  surface  of  the  female  member  at  a 
number  oJ  points  and  then  when  full  spring  pressure  is  exerted  it 


The  Modern  Gasoline  Automobile 


419 


will  overcome  the  resistance  of  the  small  radial  springs  and  the  fric- 
tion blocks  will  be  depressed  so  they  will  be  flush  with  the  surface 
of  the  male  member  which  then  takes  the  drive. 

The  cone  clutch  is  one  of  the  most  popular  forms  and  has  received 
general  application,  and  its  simple  construction  enables  the  motorist 
to  easily  understand  its  action.  As  there  are  but  few  parts  there  is 
but  little  liability  of  the  cone  clutch  giving  trouble  if  the  leather 


Flywheel. 
Friction  Shoe. 


.Clutch  Cone. 
Clutch  Spring. 


Auxiliary  Spring. 


Fig.  239.— Columbia  Clutch  Employs  Friction  Shoes  to  Grip  Fly  Wheel  Before 
Cone  is  Fully  Engaged,  to  Secure  Gradual  Application  of  Power. 

surface  is  kept  in  proper  condition.  The  chief  disadvantage  advanced 
against  cone  clutches  is  that  they  are  more  bulky  than  other  forms 
of  equal  capacity.  The  large  size  of  the  members  of  a  cone  clutch 
tend  to  make  it  "  spin  "  after  it  is  disengaged.  The  natural  tendency 
of  a  body  in  motion  is  to  continue  in  motion  until  stopped  by  some 
external  force,  which  property  is  known  as  "  inertia." 

If  two  wheels  of  the  same  weight  are  set  in  motion  by  the  expen- 


420  The  Modern  Gasoline  Automobile 

diture  of  equal  amounts  of  energy  the  one  that  has  the  weight  carried 
nearer  the  rim  or  which  is  larger  in  diameter  will  revolve  the  longest. 
The  male  member  of  a  cone  clutch,  when  released,  will  have  a  ten- 
dency to  continue  to  revolve  even  when  the  driving  pressure  is  re- 
lieved. When  sliding  gearsets  are  employed  to  obtain  the  various 
speed  ratios  it  is  imperative  that  the  engine  be  entirely  disconnected 
from  the  main  shaft  of  the  change-speed  gearing  before  any  attempt 
is  made  to  shift  the  gears.  If  the  sliding  members  are  moved  without 
first  disconnecting  the  shafts  from  the  engine  it  would  be  very  diffi- 
cult to  engage  them  and  it  might  result  in  stripping  the  teeth  from 
the  gears. 

The  average  cone  clutch  is  of  large  diameter  if  much  power  is  to 
be  transmitted  because  the  two  surfaces  in  contact  are  comparatively 
narrow.  When  the  clutch  is  released  considerable  energy  has  been 
stored  in  the  rim  of  the  cone  and  -its  tendency  is  to  keep  revolving 
and  carry  the  shaft  of  the  gearset  to  which  it  is  attached  at  the 
same  speed.  In  some  cases  it  is  difficult  to  shift  the  gears  until  the 
motion  of  the  shaft  ceases  and  it  is  either  necessary  to  wait  until 
the  momentum  of  the  clutch  cone  becomes  less  or  to  apply  some  form 
of  brake  which  will  stop  the  cone  from  rotating.  Such  brakes  are 
usually  interconnected  with  the  foot  pedal  and  act  only  when  the 
clutch  is  fully  disengaged. 

Cone-clutch  efficiency  depends  on  a  number  of  factors,  chief 
among  which  is  the  angle  of  the  cone.  The  greater  the  angle  the 
more  spring  pressure  required  because  the  wedging  effect  of  a  large 
angle  is  not  as  pronounced  as  when  more  gradual  tapers  are  employed. 
Most  cone  clutches  have  the  cone  tapering  at  an  angle  of  12  J  degrees 
and  is  not  considered  good  design  to  use  a  lesser  angle  because  the 
wedging  effect  may  make  it  extremely  difficult  to  release  the  clutch. 
At  the  other  hand,  angles  much  greater  than  15  degrees  make  it 
necessary  to  use  excessive  spring  pressure  to  maintain  proper  frictional 
adhesion  between  the  parts. 

Three-  and  Five-Plate  Clutches. — A  number  of  cars  are  provided 
with  clutches  composed  of  three  or  more  plates  of  large  diameter 
instead  of  the  use  of  two  cone  members.  It  is  claimed  that  these 
forms  make  for  very  easy  engagement  and  that  they  will  give  a  very 
prompt  releasing  action  when  the  surfaces  are  separated.  The  usual 


The  Modern  Gasoline  Automobile 


421 


construction  is  to  use  two  driving  members  which  are  carried  around 
by  the  fly  wheel  which  clamp  against  a  central-driven  member  which 
drives  the  gearset  shaft.  These  clutches  are  very  effective,,  but  one 
of  the  chief  disadvantages  is  the  same  as  that  advanced  against  the 
cone  clutch  and  that  is  the  inertia  of  the  driven  member  when  re- 
leased. When  these  clutches  are  fitted  it  is  desirable  that  they  be 
provided  with  some  form  of  a  brake  to  bring  them  to  a  stop  as  soon 
as  disengaged. 


Adjusting  Screw. 


Driving  Plate. 

Clutch  Spring  Throwout  Stud. 

Flywheel. 
Clutch  Spring. 


Crankpin. 


Fulcrum  of 
Foot  Pedal. 


Clutch  Spring 


Pressure  and  Driving  Plate. 


Driven  Plate. 
Driving  Plate. 


Fig.  240.— Three-Plate  Clutch  Utilized  on  Knox  Motor  Cars  Uses  a  Central  Driven 
Plate  Studded  with  Cork  Inserts. 

A  three-plate  clutch  which  has  been  used  successfully  on  Knox 
automobiles  is  shown  at  Fig.  240.  In  this  construction  the  clutch 
springs  are  spaced  at  equal  distances  around  the  periphery  of  the  fly 
wheel  and  bear  against  a  pressure  plate  which  is  carried  around  by 
studs  placed  just  outside  the  springs.  Two  driving  plates  are  provided 


422 


The  Modern  Gasoline  Automobile 


and  these  clamp  a  single-driven  member  attached  to  a  revolving  sleeve 
to  which  the  gearset  driving  shaft  is  keyed.  The  pressure  of  the 
springs  against  the  pressure  plate  holds  the  driven  plate  firmly  against 
the  outside  driving  plate.  When  it  is  desired  to  release  the  clutch 
the  pedal  is  depressed  and  it  pushes  the  clutch  throw-out  levers  toward 
the  fly  wheel  so  the  clutch  spring  throw-out  studs  push  the  pressure 
plate  away  from  the  driven  plate  and  allow  it  to  revolve  independent 
of  the  clutch.  The  clutch  throw-out  studs  perform  a  double  duty  in 
that  they  also  act  as  driving  members  for  the  two  driving  plates. 
The  driven  plate  is  provided  with  a  large  number  of  cork  inserts  to 
increase  its  frictional  adhesion. 


Flywheel.- 


-  Driving  Stud. 

-Driving  Plate. 

-Outer  Driven  Plate. 
-Bell  Crank. 

Clutch  Brake  Pad. 


Clutch  Throwout 
Lever. 

Gearset  Shaft. 


Flywheel 
Driving  Key. 


Driving  Coupling. 


Clutch  Brake  Drum. 
Toggle  Link. 

•Adjusting  Screw. 


Fig.  241. — A  Three-Plate  Clutch  Equipped  with  Friction  Brake  to  Arrest  Motion 
of  Driven  Member  when  Clutch  is  Released. 

Another  form  of  three-plate  clutch  in  which  there  are  two  driven 
plates  and  sone  driving  member  is  shown  at  Fig.  241.  The  driving 
plate  is  carried  around  by  a  number  of  studs  spaced  around  the  fly- 


The  Modern  Gasoline  Automobile 


423 


wheel-rim  face.     The  driven  member  nearest  the  fly  wheel  carries  a 
number  of  arms  to  which  small  bell  cranks  are  fulcrumed.     These 


Flywheel. 

Flywheel  Stud. 
—  Driven  Plates. 

./•  Adjusting  Screw. 


Ball  Bearing 
Supporting  - 
Driven  Mem- 
ber. 


Crankshaft. 


Clutch  Throwout. 


Driving  Plates. 
Driving  Stud. 


Fig.  242.— Five-Plate  Clutch  which  Employs  Two  Driving  Members  Attached 
to  Fly  Wheel  and  Three  Driven  Plates. 

arms  also  act  as  a  support  for  the  outer  driven  plate.     The  clutch 
spring  bears  against  a  sliding  member  which  forces  the  ends  of  the 


424  The  Modern  Gasoline  Automobile 

bell  crank  to  which  it  is  connected  by  a  series  of  toggle  links  out- 
wardly, and  clamps  the  driving  plate  firmly  between  the  inner  and 
outer  driven  plates.  When  the  clutch  spring  is  depressed  the  bell 
cranks  drop  back  and  the  pressure  between  the  driving  plate  and 
the  faces  of  the  driven  members  is  relieved.  When  this  condition 
exists  the  driving  plate  turns  with  the  fly  wheel  but  does  not  pro- 
duce movement  of  the  driven  members  to  which  the  gearset  shaft  is 
attached  by  a  semiuniversal  driving  coupling.  When  'the  clutch 
throw-out  lever  is  moved  away  from  the  fly  wheel  to  release  the  clutch 
it  brings  a  small  brake  pad  in  contact  with  a  drum  carried  by  the 
driven  member  and  stops  its  rotation.  When  the  parts  are  as  shown 
in  illustration,  the  driving  plate  is  firmly  clamped  between  the  driven 
members  and  the  power  of  the  engine  is  being  transmitted  directly  to 
the  gearset  shaft. 

In  order  to  obtain  more  driving  surface  some  designers  have 
used  five  plates  instead  of  three.  A  five-plate  clutch  which  operates 
on  the  same  general  principle  as  the  three-plate  type  previously  de- 
scribed is  shown  at  Fig.  242,  In  this,  two  driving  plates  are  carried 
by  studs  set  into  the  fly-wheel  face  and  the  three  driven  members  are 
kept  in  engagement  by  means  of  bell  cranks  and  toggle-link  action. 
The  reason  that  five  disks  are  used  instead  of  three  is  that  the  aug- 
mented surface  makes  it  possible  to  reduce  the  spring  pressure  to 
some  extent  and  makes  for  easier  operation  when  it  is  desired  to  dis- 
engage the  clutch.  When  the  driving  contact  between  the  clutch 
pjates  is  interrupted  the  member  to  which  the  gearset  shaft  is 
attached  is  kept  stationary  and  the  fly-wheel  hub  and  crank-shaft 
extension  revolve  freely  because  anti-friction  bearings  of  the  ball  type 
are  interposed  between  the  members. 

Features  of  Multiple-Disk  Clutches. — Power  transmission  by  plates 
is  sometimes  accomplished  by  using  a  large  number  of  small  diameter 
disks  instead  of  the,  smaller  number  of  large  plates.  The  multiple- 
disk  type  offers  several  advantages  not  found  in  other  forms,  as  it  is 
the  most  compact  form  of  clutch.  The  required  contact  area  is  ob- 
tained by  using  a  multiplicity  of  comparatively  small  surfaces  in 
preference  to  two  large  ones  as  is  the  case  with  the  cone  clutch  or 
the  greater N  number  possible  when  three-  or  five-plate  clutches  are 
employed. 


The  Modern  Gasoline  Automobile  425 

The  type  of  multiple -disk  clutch  that  seems  to  be  most  widely 
employed  consists  of  a  number  of  soft  steel  disks  which  sometimes 
alternate  with  others  of  different  material  such  as  phosphor  bronze. 
One  set  of  these  disks  is  driven  by  the  engine  while  the  remaining 
plates  are  attached  to  a  floating  member  to  which  the  transmission 
sjiaft  is  joined.  Pressure  is  usually  obtained  from  a  coil  spring 
which  acts  against  one  of  the  disks,  which  in  turn  acts  upon  the 
neighboring  one.  It  is  common  practice  to  house  a  clutch  of  this 
type  in  an  oil-tight  case,  which  insures  that  the  members  will  always 
be  kept  in  an  oil  bath.  Oil  performs  the  dual  function  of  securing 
easy  engagement  by  interposing  a  cushion  between  the  metal  elements 
arid  also  to  prevent  wear  because  of  its  value  as  a  lubricant. 

As  multiple-disk  clutches  are  usually  of  small  diameter,  the  inertia 
of  the  driven  member  is  small  compared  to  that  of  a  cone  or  large 
plate  type,  and  the  spinning  tendency  is  reduced.  The  spring  pres- 
sure is  usually  sufficient  to  squeeze  the  oil  from  the  plate  as  soon  as 
engagement  is  fully  made  and  a  metal  to  metal  contact  then  obtains. 
The  fact  that  the  lubricant  is  gradually  forced  out  and  that  there 
will  be  a  certain  amount  of  slipping  as  long  as  any  of  the  lubricant 
remains  means  that  the  power  will  be  applied  in  a  gradual  manner 
even  if  the  clutch  is  carelessly  operated.* 

.  While  a  multiple-disk  clutch  does  not  have  a  tendency  to  spin 
because  of  inertia,  the  plates  may  sometimes  refuse  to  disengage  be- 
cause of  a  partial  vacuum  existing  between  them,  produced  when  the 
oil  film  was  forced  out.  This  sometimes  causes  the  plates  to  adhere 
together.  This  trouble  is  rare  in  well-designed  clutches  and  is  sel- 
dom present  unless  poor  lubricating  oil  is  used  between  the  plates. 
This  drag  and  consequent  trouble  in  shifting  gears  is  more  apt  to 
occur  on  forms  which  employ  flat-stamped  plates  without  spring 
tongues  to  separate  them  when  the  spring  pressure  is  relieved.  Mul- 
tiple-disk clutches  are  sometimes  provided  with  plates  having  cork 
inserts,  while  others  have  a  number  of  the  disks  faced  with  some 
friction  material  such  as  the  asbestos-wire  fabric  and  are  designed 
to  run  dry  instead  of  in  an  oil  bath. 

A  typical  multiple-disk  clutch  is  shown  at  Fig.  243.  In  this 
member  the  clutch  case  is  cast  integral  with  the  fly  wheel  and  forms 
the  fly-wheel  hub.  A  series  of  disks  are  carried  by  a  driving  drum 


426 


The  Modern  Gasoline  Automobile 


and  are  kept  in  engagement  with  those  carried  around  by  the  fly 
wheel  by  means  of  pressure  derived  from  a  coil  spring  which  is  let 
into  a  bored-out  recess  at  the  end  of  the  crank  shaft.  The  clutch 
depicted  is  intended  to  run  in  oil  and  a  number  of  the  plates  are 


Flywheel. 

Disc  Assembly. 


Shaft  in  Gear  Set. 


Fig.  243. — Typical  Multiple-Disk  Clutch  Assembly.     The  Form  Illustrated  is 
Used  on  Some  of  the  Hudson  Cars. 

provided  with  cork  inserts.  The  multiple-disk  clutch  depicted  at 
Fig.  244 -is  that  used  on  Franklin  cars,  and  is  a  form  in  which  all 
metal  plates  running  in  oil  are  used.  That  depicted  at  Fig.  245  is 


Flywheel; 
Clutch  Discs. 


Spring. 


Fig.  244. — Multiple-Disk  Clutch  Utilized  on  Franklin  Automobiles  is  Housed  in 
Blower  Fly  Wheel.  Parts  are  Shown  Separated  to  Make  Construction 
Clear. 


Plate  with  Cork  Inserts. 


Driving  Discs. 


Fig.  245.— Clutch  of  Premier  Cars  Uses  Multiple  Disk  Studded  with  Cork  In- 
serts as  Driving  Members,  and  Plain  Metal  Plates  as  Driven  Elements. 

427 


428  The  Modern  Gasoline  Automobile 

used  on  Premier  cars  and  one  set  of  plates  is  provided  with  a  large 
number  of  cork  inserts  to  promote  easy  engagement,  positive  drive,  and 
prompt  release. 

While  the  clutch  forms  described  are  the  most  common,  a  few 
cars  have  been  provided  with  internal  expanding  band  clutches  or 
external  constricting  band  forms.  The  internal  member  consists  of 
a  steel  band  or  shoe  faced  with  leather  or  other  frictional  material 
or  provided  with  cork  inserts  which  expands  against  the  inner  periph- 
ery of  a  drum  integral  with  the  fly  wheel.  The  band  is  expanded 
by  spring  pressure  which  spreads  the  driven  member  either  by  toggle 
linkage  or  a  right  and  left  hand  quick-acting  screw. 

Planetary  gearsets  employ  external  constricting  bands  to  stop 
rotation  of  the  gear  drums,  but  these  should  properly  be  considered 
under  the  head  of  brakes  rather  than  clutches.  The  disadvantage  of 
either  internal  or  external  band  clutches  is  that  they  are  very  hard 
forms  to  balance  and  the  internal  expanding  band  is  especially  sus- 
ceptible to  the  influence  of  wear  and  oil  between  the  surfaces.  The 
external  band  provides  a  very  gradual  clutching  action,  but  owing  to 
the  difficulty  in  balancing  it  because  of  the  unsymmetrical  operating 
mechanism  usually  employed,  it  has  not  been  used  to  any  extent  in 
this  country.  With  the  forms  described  no  difficulties  are  present 
as  relates  to  balancing,  and  as  the  band  forms  have  no  apparent' ad- 
vantages when  compared  to  the  better  developed  cone  and  plate  types 
there  seems  to  be  no  reason  for  further  development  of  forms  which 
are  good  in  theory  but  hard  to  apply 'in  a  practical  manner. 

Why  Change-Speed  Gearing  is  Necessary. — Those  who  are  familiar 
with  steam  or  electricity  as  sources  of  power  for  motor  vehicles 
may  not  understand  the  necessity  for  the  change-speed  gearing  which 
is  such  an  essential  component  of  the  automobile  propelled  by  in- 
ternal combustion  motors.  In  explaining  the  reason  for  the  use  of 
the  clutch  it  ha,s  been  demonstrated  that  steam  or  electric  motors 
were  very  flexible  and  that  their  speed  and  consequently  the  power 
derived  from  them  could  be  varied  directly  by  regulating  the  amount 
of  energy  supplied  from  the  steam  boiler  or  the  electric  battery, 
as  the  case  might  be. 

If,  for  example,  we  compare  the  steam  motor  with  the  explosive 
engine  it  will  be  evident  that  the  power  is  produced  in  the  former 


The  Modern  Gasoline  Automobile  429 

by  the  pressure  of  steam  admitted  to  the  cylinders  as  well  as  the 
quantity  and  the  speed  of  rotation.  When  the  engine  is  running 
slowly  and  a  certain  amount  of  power  is  needed  more  steam  can  be 
supplied  the  cylinders  and  practically  the  same  power  obtained  as 
though  the  steam  pressure  was  reduced  and  the  engine  speed  in- 
creased. The  internal  combustion  motor  is  flexible  to  a  certain  de- 
gree, providing  that  it  is  operating  under  conditions  which  are 
favorable  to  accelerating  the  motor  speed  by  admitting  more  gas  to 
the  cylinders.  There  is  an  arbitrary  limit,  however,  to  the  power 
capacity  or  the  mean  effective  pressure  of  the  explosion,  and  beyond 
a  certain  point  it  is  not  possible  to  increase  the  power  by  supplying 
vapor  having  a  higher  pressure  as  is  possible  with  a  steam  engine. 

In  an  explosive  motor  we  can  increase  the  power  after  the  maxi- 
mum throttle  opening  has  been  reached  only  by  augmenting  the 
number  of  revolutions.  Whereas  it  is  possible  to  gear  a  steam  engine 
or  an  electric  motor  directly  to  the  driving  wheels,  it  is  not  possible 
to  do  this  with  a  gasoline  engine,  and  some  form  of  gearing  must  be 
introduced  between  the  motor  and  the  driving  wheels  in  order  that 
the  speed  of  one  relative  to  the  other  may  be  changed  as  desired  arid 
the  engine  crank  shaft  turned  at  speeds  best  adapted  to  produce  the 
power  required,  and  to  allow  the  rear  wheels  to  turn  at  speeds  dictated 
by  the  condition  of  the  roads  or  the  gradients  on  which  the  car  is 
operated. 

It  is  customary  in  all  automobiles  of  the  gasoline-burning  type, 
where  combustion  takes  place  directly  in  the  cylinders,  to  interpose 
change-speed  gearing  which  will  give  two  or  more  ratios  of  speed 
between  the  engine  and  the  road  wheels.  As  it  is  not  possible  to 
reverse  the  automobile  engine  utilized  in  conventional  cars,  it  is  neces- 
sary to  add  a  set  of  gears  to  the  gearset  to  give  the  wheels  a  reverse 
motion  when  it  is  desired  to  back  the  conveyance. 

Many  methods  of  varying  the  ratio  of  speed  between  the  engine 
and  traction  members  have  been  evolved,  but  few  speed-changing 
mechanisms  have  survived.  At  the  present  time  the  majority  of 
automobile  makers  employ  sliding  gear  transmissions  which  are  al- 
most invariably  of  the  selective  type.  One  or  two  cars  are  fitted  with 
simple  face  friction  gearing  and  a  limited  number  provide  two  for- 
ward speeds  and  a  reverse  motion  by  using  planetary  gearing. 


430 


The  Modern  Gasoline  Automobile 


At  one  of  the  recent  automobile  shows  held  at  New  York,  385 
models  of  cars  were  exhibited,  and  of  this  number  but  a  very  small 
percentage  used  change-speed  gearing  that  differed  radically  from 
standard  practice.  Of  this  number  347  models  were  equipped  with 
selective  sliding  gear  transmissions  and  six  cars  used  progressive  slid- 
ing gearing.  Thirteen  models  utilized  planetary  transmissions  and 
friction  change-speed  gearing  was  supplied  in  nineteen  instances. 
While  the  sliding  gear  form  of  transmission  is  without  doubt  the  most 
unmechanical  and  brutal  of  all  speed  gearing,  if  considered  from  a 
purely  theoretical  viewpoint,  the  very  satisfactory  service  which  is 
secured  in  actual  use  justifies  its  general  application,  especially  at  the 
present  time  when  engineers  are  so  thoroughly  conversant  with  details 
of  design  and  motor-car  drivers  have  been  so  well  trained  to  operate 
gears  of  this  character  with  proper  care. 

Face  Friction  Gearing. — A  form  of  gearing  that  has  many  ad- 
herents because  of  its  simple  design  and  easy  operation  employs  two 
friction  disks  which  are  held  together  by  sufficient  pressure  to  cause 


Frame 


Bearing 


Sprocket 

Wheel          Aluminum 
A  Driving  Disc 


Fig.  246. — Outlining  Action  of  Simple  Face  Friction  Gearing,  which  Combines 
Clutching  and  Speed-Changing  Functions. 

one  of  these  members  to  turn  the  other.  This  was  one  of  the  earliest 
forms  of  gearing  used,  and  while  it  was  abandoned  for  a  time  because 
of  defects  of  a  purely  technical  nature  continual  experiments  made 
possible  a  combination  of  materials  which  gave  satisfactory  results 
in  practice.  • 

The  rolling  traction,  or  friction  transmission,  as  it  is  commonly 
called  in  its  simplest  form,  is  shown  at  Fig.  246,  A.  It  consists  of 
two  disks  or  plates,  one  faced  with  an  aluminum-copper  alloy  driven 


The  Modern  Gasoline  Automobile  431 

by  the  engine  and  a  wheel  which  is  provided  with  a  strawboard 
fiber  driving  ring  mounted  on  a  cross  shaft  at  right  angles  to  the 
crank  shaft  of  the  power  plant.  The  cross  shaft  is  journaled  in  anti- 
friction bearings  and  the  driven  disk  or  plate  can  be  moved  axially 
so  as  to  engage  with  different  portions  of  the  aluminum  driving  disk. 
The  driving  member  is  mounted  on  a  sliding  shaft  which  can  be 
moved  toward  the  driven  member  and  held  in  contact  by  a  definite 
amount  of  pressure  or  pulled  away  when  it  is  desired  to  interrupt 
the  drive.  In  this  manner  both  clutching  and  speed-changing  func- 
tions are  combined  in  one  simple  mechanism. 

The  method  by  which  various  speed  changes  may  be  secured  is 
demonstrated  at  Fig.  246,,  B.  The  driven  member  is  shifted  across 
the  face  of  the  driving  disk  so  it  can  engage  different  portions  at 
varying  distances  from  the  center.  As  the  wheel  is  moved  from 
the  center  toward  the  outer  periphery  the  speed  ratios  increase  in 
proportion  to  the  amount  the  disk  is  moved  out.  If  the  driven  disk 
is  moved  over  to  the  other  side  of  the  driving  disk  and  past  the 
central  point  a  reverse  motion  will  be  obtained  when  driving  contact 
is  again  established  between  the  surfaces.  To  interrupt  the  drive 
the  members  are  separated  and  when  the  faces  are  brought  together 
the  frictional  adhesion  permits  one  to  drive  the  wheels. 

Assume  that  both  disks  are  sixteen  inches  in  diameter  and  that  the 
driven  member  has  moved  away  from  center  until  it  engages  a  point 
having  a  mean  radius  of  two  inches  from  the  center  line.  The  disk 
would  be  moved  from  position  B  in  which  it  is  placed,  as  shown  in 
illustration,  to  position  indicated  by  the  dotted  rectangle  D.  In  this 
case  the  driving  effect  would  be  just  the  same  as  though  a  four-inch 
diameter  wheel  was  engaged  with  the  sixteen-inch  diameter  driven 
member.  This  would  give  a  low  gear  ratio  because  the  engine  would 
be  turning  at  four  times  the  speed  of  the  driven  member.  If  driving 
contact  was  again  broken  and  the  driven  wheel  moved  along  the 
shaft  until  it  occupied  the  position  indicated  by  the  rectangle  E, 
the  effect  would  be  the  same  as  though  an  eight-inch  driving  member 
was  turning  the  sixteen-inch  driven  wheel.  This  would  give  a  higher 
ratio  than  in  the  case  previously  described,  as  the  engine-  shaft  would 
only  turn  at  twice  the  speed  of  the  driven  member. 

If  the  driven  member  was  moved  so  that  it  occupied  position  G, 


432 


The  Modern  Gasoline  Automobile 


the  highest  speed  wtfuld  be  obtained  because  the  disks  would  be  turn- 
ing at  equal  speed  as  one  sixteen-inch  wheel  would  be  turning  another 
one  of  the  same  diameter.  If  the  disk  was  moved  back  to  the  other 
side  of  center  or  from  position  B?  to  that  shown  by  the  rectangle  C, 


Driving  Disc. 


Driven  Disc. 


M 


Drive  Shaft. 


Engine. 


Driving  Disc. 
Slip  Joint. 

^Flywheel. 


Differential. 
Countershaft. 

Driven  Wheel. 


B 


\ 


Chain. 


Fig.  247.— How  Face  Friction  Gearing  is  Installed  in  Motor-Car  Chassis.  A — 
Arranged  for  Shaft  Drive.  B — Power  Transmitted  to  Wheels  by  Side 
Chains. 

the  driven  wheel  would  be  turned  at  one  fourth  the  engine  speed  and 
in  a  reverse  direction. 

This  form  of  gearing  is  not  generally  used  for  high-powered  cars 
because  the  driving  wheel  must  be  of  large  diameter  and  very  bulky 
to  transmit  the  higher  powers.  The  amount  of  energy  it  is  possible 
to  transmit  efficiently  depends  upon  the  nature  and  size  of  the  sur- 


The  Modern  Gasoline  Automobile 


433 


faces  in  contact  and  the  amount  of  pressure  which  is  exerted  to  bring 
the  friction  members  together.  When  a  friction  transmission  is 
used  it  is  usually  applied  in  connection  with  single-  or  double-chain 
drives  to  the  rear  wheels,  though  forms  have  been  devised  where  driv- 
ing by  shaft  and  bevel  gears  is  possible. 

The  application  of  a  friction  transmission  to  a  shaft-drive  chassis 
is  shown  at  Fig.  247,  A.  In  this  the  double-opposed  motor  is  mounted 
so  the  crank  shaft  is  at  right  angles  to  the  frame  side  member  while 
the  cross  shaft  on  which  the  driven  disk  slides  is  parallel  with  the 
frame  side.  The  aluminum-alloy  driving  disk  is  attached  directly  to 
the  fly  wheel  of  the  motor,,  while  the  fiber-faced  friction  wheel  is 
carried  on  a  countershaft  so  journaled  that  the  entire  shaft  may  be 
swung  over  and  bring  the  driven  disk  in  contact  with  the  driving 
member.  A  shaft  serves  to  connect  the  driven  disk  shaft  to  bevel 
gearing  in  the  rear  axle. 

At  Fig.  247,  B,  the  method  of  installation  when  a  double-chain 
drive  is  provided  is  shown,  while  at  Fig.  248  the  layout  of  a  friction 
gearing  employing  single-chain  drive  is  outlined.  The  relation  of 
the  parts  to  each  other  can  be  very  easily  understood  by  referring 


Fig.  248. — Disposition  of  Important  Elements  of  Simple  Face  Friction  Gearing 
Adapted  for  Single-Chain  Drive. 

to  the  illustrations.  In  the  system  depicted  at  Fig.  248  the  double- 
cylinder  engine  is  placed  in  the  frame  in  such  a  way  that  the  crank 
shaft  is  parallel  with  the  frame  side  member.  The  drive  from  the 
engine  crank  shaft  is  through  a  sliding  coupling  at  one  end  of  the 


434  The  Modern  Gasoline  Automobile 

shaft  which  carries  the  aluminum  driving  disk.  This  member  is 
hacked  by  a  ball-thrust  bearing  which  in  turn  forms  part  of  a  sliding 
sleeve  or  bushing  connected  to  the  small  arm  of  a  lever  which  is 
joined  to  the  foot  pedal.  When  the  long  arm  of  the  lever  is  moved 
in  the  direction  of  the  arrow  the  sliding  coupling  is  pushed  in  a 
reverse  direction  and  the  pressure  exerted  against  the  aluminum  disk 
brings  it  in  contact  with  the  fiber-faced  wheel  on  the  countershaft. 
The  driven  wheel  is  moved  along  the  countershaft  by  means  of  a  long 
bell  crank,  the  short  end  of  which  goes  to  the  control  lever  while  the 
long  end  is  employed  to  swing  the  fiber-faced  wheel  along  the  coun- 
tershaft. The  drive  from  the  countershaft  is  by  means  of  chain 
and  sprocket  connection  with  a  live  rear  axle. 

In  the  form  shown  at  Fig.  247,  B,  the  rear  axle  is  a  stationary 
member  and  the  wheels  are  driven  independently  by  means  of 
sprockets  carried  by  the  axle  shafts  of  the  compound  countershaft, 
which  is  in  reality  a  live  axle  mounted  on  the  frame  members  and 
carrying  the  differential  gear.  As  the  power  transmitted  is  directly 
proportional  to  the  pressure  maintaining  contact  between  the  sur- 
faces it  is  imperative  that  the  leverage  employed  to  produce  this  pres- 
sure be  very  substantial  and  rigid.  Tests  have  demonstrated  that 
the  best  combination  of  surfaces  is  a  strawboard  fiber  driving  ring 
against  an  aluminum  or  copper-alloy  driving  plate,  and  these  are  the 
materials  commonly  used. 

This  form  of  gearing  has  the  advantage  that  it  is  easily  handled 
by  the  novice  and  it  is  difficult  to  injure  it  by  careless  manipulation. 
The  number  of  forward  speeds  provided  are  infinite,  as  the  driven 
member  may  be  moved  across  the  driving  face  very  gradually  and 
engage  driving  circles  which  vary  by  small  increments.  The  sur- 
faces must  be  kept  clean  and  free  from  grease  or  the  gearing  will 
slip,  and  for  this  reason  this  form  is  not  so  generally  used  as  one 
might  suppose,  if  its  value  was  judged  only  by  its  simplicity  and  ease 
of  operation. 

How  Planetary  Gearing  Operates. — The  planetary  or  epicyclic 
transmission  is  an  easily  operated  form  of  speed  gear  that  has  been 
very  popular  on  small  cars.  This  has  many  features  of  merit,  it 
provides  a  positive  drive,  and  as  the  gears  are  always  in  mesh  these 
members  cannot  be  injured  by  careless  shifting.  Individual  clutches 


The  Modern  Gasoline  Automobile 


435 


are  used  for  each  speed  and  as  the  operation  of  the  clutch  occurs 
at  the  same  time  that  the  desired  speed  is  selected  the  various  speed 
changes  desired  may  be  easily  effected  by  manipulating  a  single  lever 
if  desired. 

A  typical  planetary  gearing  of  simple  form  which  was  formerly 
used  on  Oldsmobile  cars,  which  were  one  of  the  earliest  makes  to 


Brake  Drum. 

Brake 


Low  Speed 


Direct  Drive 
Clutch. 


Clutch  Cone 


Low  Speed  Dram. 


Fig.  249. — Sectional  View  of  Simple  Planetary  Gearset. 

be  manufactured  in  large  quantities,  is  outlined  at  Fig.  249.  The 
gearing  is  carried  in  drums  which  are  adapted  to  be  revolved  inde- 
pendently of  each  other  or  to  be  clamped  by  some  form  of  clutch 
which  would  cause  them  to  revolve  as  a  unit  with  the  crank  shaft. 


436  The  Modern  Gasoline  Automobile 

The  drive  is  by  single  chain  from  a  sprocket  carried  between  the 
brake  and  reverse  drum  and  the  gearing  was  mounted  on  a  crank- 
shaft extension  which  projected  from  the  fly  wheel  of  the  motor. 
The  drum  nearest  the  fly  wheel  carries  three  pinions  which  mesh  with 


Internal  Gear 


Idler  Pinion 


Fig.  250. — Demonstrating  Action  of  Epicyclic   Gearing.    A — The  Slow-Speed 
Gear  Assembly.    B — Gears  and  Pinions  Used  for  Reverse  Drive. 

an  internal  gear  member  secured  to  the  sprocket  and  with:  a  gear 
driven  by  the  fly-wheel  hub.  The  slow-speed  drum  is  provided  with 
four  pinions  which  are  carried  around  by  a  disk  which  is  also  secured 
to  the  driving  sprocket.  In  the  reverse  gear  combination  the  disk 
that  carried  the  pinions  was  provided  with  ttye  brake  member,  while 
in  the  slow-speed  gearing  it  was  the  internal  gear  which  was  held 
from  turning  when  the  slow-speed  ratio  was  desired. 

The  master  clutch,  which  provided  the  direct  drive,  consisted  of 
four  fingers  provided  with  leather  friction  pads  which  were  forced 
against  the  face  of  the  internal  gear  drum  of  the  slow  speed  by  means 
of  clutch  dogs  expanded  by  a  sliding  cone.  When  the  clutch  cone 
was  forced  in  so  that  the  small  bell  cranks  brought  the  friction  pads 
in  contact  with  the  face  of  the  slow-speed  drum,  the  entire  assembly 
was  firmly  locked  to  the  crank  shaft  and  a  direct  drive  obtained  as  the 
sprocket  turned  at  the  same  speed  as  the  engine  shaft. 

The  meihod  by  which  the  slow  and  reverse  speeds  may  be  obtained 
and  the  arrangement  of  the  planetary  gearing  is  clearly  shown  at  Fig. 


The  Modern  Gasoline  Automobile 


437 


250.  At  A  the  slow'-speed  gearing  is  shown  while  the  reverse  gear 
arrangement  is  outlined  at  B.  The  driving  gear  or  center  member 
in  both  cases  is  keyed  to  and  turns  with  the  crank  shaft.  With  the 
combination  shown  at  A,  when  the  slow  speed  is  desired  the  internal 
gear  is  kept  from  revolving  by  means  of  a  constricting  brake  band 
which  grips  its  outer  periphery,  and  the  small  planetary  pinions  are 
forced  to  turn  around  on  their  supporting  studs  and  carry  the  disk 
by  which  they  are  supported  and  which  is  attached  to  the  driving 
sprocket  in  the  same  direction  as  the  main  driving  gear,  but  at  a 
slower  speed.  The  gear  reduction  obtained  depends  upon  the  ratio 
of  the  driving  and  internal  gear  members. 

When  the  reverse  gearing  is  desired  the  mode  of  operation  is 
different.  The  conditions  are  then  as  shown  at  B.  In  this  case 
it  is  the  disk  carrying  the  pinion-supporting  pins  which  is  kept 
from  rotating.  The  driving  gear  turns  the  idler  pinions  in  a  reverse 
direction,  and  these  in  turn  cause  the  internal  gear  to  which  the 
sprocket  is  fastened  to  turn  in  a  direction  opposite  to  that  of  crank- 
shaft rotation  and  at  considerably  lower  speed. 


Reverse  Drum. 


Brake  Drum. 


Thrust  Bearing1, 


Slow  Speed  Drum. 
Spur  Driven  Gears. 
High  Speed  Clutch  Disc. 
Adjustment  Lock  Screw. 
High  Speed  Clutch  Spider. 
High  Speed  Cone. 

Engine  End. 


High  Speed 
Finger. 


Spur  Driving  Gears. 


Fig.  251.— Planetary  Gearing  Utilizing  Only  Spur  Gears  Carried  in  Oil-Tight 

Case. 

Other  forms  of  planetary  gearing  have  been  evolved  in  which  the 
internal  gears  have  been  eliminated  and  in  which  the  gear  ratios 


438 


The  Modern  Gasoline  Automobile 


are  provided  by  a  train  of  spur  gears.  A  gearset  of  this  form  is 
shown  at  Fig.  251,  and  as  all  parts  are  clearly  indicated  it  will  not 
be  necessary  to  describe  its  action  in  detail  because  it  is  very  much 
the  same  as  that  of  the  form  previously  described.  When  the  slow 
speed  is  desired  a  brake  band  is  clamped  around  the  slow-speed  drum, 


Flywheel. 

Clutch  Discs. 


Clutch  Spring. 


>w  Speed  and  Reverse  Bands. 
Planetary  Gears. 


Fig.  252. — Two-Speed  and  Reverse  Planetary  Gear  Employed  on  Ford  Auto- 
mobiles. 

and  a  similar  member  constricted  around  the  reverse  drum  will  give 
the  reverse  motion.  The  gearing  is  locked  together  by  means  of  a 
face-friction  clutch,  which  is  pressed  in  contact  with  the  slow-speed 
drum  face  by  means  of  a  high-speed  locking  cone  and  cone-operated 


The  Modern  Gasoline  Automobile  439 


dogs  or  bell  cranks.  The  form  shown  is  intended  to  work  in  connec- 
tion with  shaft  drive,  and  a  universal  joint  is  attached  to  the  squared 
driving  end. 

The  planetary  gearing  shown  at  Fig.  252  is  that  used  in  Ford 
automobiles  and  its  operation  is  similar  to  the  forms  previously  de- 
scribed. In  this  mechanism,  however,  the  master  clutch  which  pro- 
vides the  direct  drive  is  a  multiple-disk  form  composed  of  steel  disks, 
which  are  kept  in  permanent  contact  and  proper  driving  relation  by 
means  of  a  heavy  coiled  spring.  The  low  and  reverse  speeds  are 
obtained  in  the  conventional  manner  by  tightening  the  external  con- 
tracting clutch  bands,  which  are  shown  between  the  gearing  and  disk 
clutch. 

Planetary  gearing  has  been  very  successful  when  properly  designed 
and  installed,  and  its  chief  disadvantage  is  that  it  is  very  difficult  to 
provide  more  than  two  forward  speeds  and  one  reverse.  For  this 
reason  it  can  only  be  adapted  to  light  cars  which  have  a  surplus  of 
power  in  the  engine,  or  to  heavy  trucks  where  it  is  not  so  essential 
that  a  large  number  of  speed  ratios  be  provided  as  in  touring  cars. 
Such  gearing  is  not  efficient  on  low  and  reverse  speeds  as  considerable 
power  is  absorbed  in  friction,  but  when  on 'the  high  speed  or  direct 
drive  it  is  superior  to  any  other  form  of  change-speed  gearing  because 
the  entire  assembly  is  locked  to  the  crank  shaft,  no  gears  are  turning 
idly,  and  the  weight  of  the  gearing  serves  merely  as  an  additional 
fly-wheel  member.  Considerable ,  trouble  was  experienced  with  the 
early  forms  because  it  was  difficult  to  keep  oil  in  the  case,  but  in  mod- 
ern forms  special  care  has  been  taken  in  housing  the  reduction  gears 
so  these  are  constantly  oiled,  and  both  wear  and  noise,  which  were 
formerly  detrimental  to  the  adoption  of  this  form  of  gearing  and 
which  militated  largely  against  its  general  use,  have  been  eliminated. 

Individual  Clutch  Transmission. — A  form  of  gearset  which  com- 
bines the  good  features  of  the  planetary  type  in  that  the  driving  gears 
are  always  in  mesh  and  which  can  be  provided  with  any  desired  num- 
ber of  speed  ratios  is  known  as  the  individual  clutch  type.  In  gear- 
sets  of  this  form  one  set  of  gears  is  carried  by  the  countershaft  and 
is  fixed  thereto  while  another  set  of  gears,  with  which  these  members 
mesh,  revolve  idly  on  the  main  driving  shaft. 

A  transmission  of  this  type  which  has  been  applied  successfully 


440 


The  Modern  Gasoline  Automobile 


in  motor-truck  design  is  shown  at  Fig.  253.  In  this  the  power  is 
delivered  to  a  main  shaft,  which  is  supported  on  ball  bearings  and 
which  carries  a  bevel  pinion  engaged  with  a  bevel  gear  for  driving 
the  wheels  at  the  rear  end.  The  gears  mounted  on  the  main  shaft 
are  normally  free  to  revolve  independently  from  the  shaft  unless 
they  are  clutched  to  it  by  sliding  positive  jaw  clutch  members  driven 


Countershaft 


w  Speed  Pinion 


High  and  Intermediate 
Low  and  Reverse  Clutch  Clutch 


Fig.  253. — Part  Sectional  View  of  Cotta  Individual  Clutch  Transmission  Designed 
for  Heavy  Motor  Truck. 

by  the  main  shaft.  Any  desired  speed  ratio'  may  be  selected  by  en- 
gaging the  gear  desired  by  means  of  the  clutch  carried  at  its  side, 
thus  causing  it  to  turn  with  the  shaft. 

When  the  clutches  are  placed  as  shown  in  illustration,  the  gears 
are  neutral  and  the  driving  shaft  turns  without  producing  movement 
of  the  bevel  driving  gears.  If,  it  is  desired  to  engage  the  low  speed 
the  low  and  reverse  clutch  member  is  moved  toward  the  front  end  of 
the  gearset  until  it  clutches  the  low-speed  gear  to  the  main  shaft. 
The  power  of  the  engine  is  then  applied  to  the  countershaft  through 
the  constant  mesh  gears  at  the  extreme  front  end  of  the  gearset 
and  as  the  main  shaft  is  made  in  two  pieces,  the  end  of  one  member 
telescoping  into  the  portion  that  carries  the  driving  connection  to 
the  engine,  the  drive  is  back  from  the  countershaft  low-speed  pinion 
to  the  big  gear  which  has  been  clutched  to  the  main  shaft  and  which 
causes  it  to  turn  slower  than  the  driving  member  attached  to  the 
engine. 


The  Modern  Gasoline  Automobile 


441 


To  obtain  a  reverse  ratio  the  low  and  reverse  clutch  is  moved  to 
the  back  end  of  the  transmission  and  the  reverse  gear  is  locked  to 
the  main  shaft.  To  obtain  direct  forward  drive  the  high  and  inter- 
mediate clutch  member  is  pushed  forward  until  it  engages  the  teeth 
on  the  side  of  the  constant  mesh  gear.  This  operation  locks  both 
portions  of  the  main  shaft  together  and  causes  that  part  to  which 
the  bevel  driving  pinion  is  secured  to  turn  at  the  same  speed  of 
rotation  as  the  driving  end  which  is  joined  to  the  engine.  The 
clutches  are  arranged  in  such  a  manner  that  only  one  can  be  used  at  a 
time  and  in  addition  to  the  positive  clutches  carried  in  the  gear  case 
some  form  of  master  clutch,  which  is  invariably  of  the  friction  type, 
must  be  provided  between  the  power  plant  and  the  gearset. 


.Silent  Chain. 


Countershaft. 


Constant  Drive 
Chai 


ve  End. 


Intermediate. 


Low. 


Reverse  Gears> 


Fig.  254. — Individual  Clutch  Transmission  Using  Silent  Chain  Connection  Be- 
tween Main  and  Countershafts  for  Forward  Speeds  and  Sliding  Spur  Gears 
for  Reverse  Action. 

There  is  a  growing  tendency  to  apply  the  silent  chain  to  positive 
individual  clutch  types  of  transmissions  instead  of  utilizing  direct 
gcjir  connection.  The  application  of  silent  chains  to  a  gear  box  is 
shown  at  Fig.  254,  and  the  sectional  view  which  is  shown  at  Fig.  255 
makes  the  method  of  operation  clear.  The  advantage  of  the  silent 


442 


The  Modern  Gasoline  Automobile 


chain  when  used  in  gear  boxes  of  this  character  is  that  it  provides 
a  more  silent  drive  than  direct  gear  connection  would.  This  is  very 
valuable  in  the  case  of  heavy,  low-powered  cars  such  as  omnibuses 
and  commercial  vehicles,  where  the  gearing  is  frequently  used  and 
where  the  vehicles  are  operated  for  the  most  part  under  traffic  con- 
ditions which  make  noisy  operation  undesirable.  The  method  of 
operation  when  silent  chains  are  used  is  exactly  the  same  as  though 
the  drive  was  by  spur  gearing. 

Referring  to  the  sectional  view  of  the  gear  box  given  at  Fig.  255, 
it  will  be  seen  that  the  power  from  the  motor  is  delivered  to  a  drive 


Countershaft  Drive  Gear. 

Intermediate. 


Low  Pinion. 


ntershaft. 
Reverse  Pinion. 


Brake. 


High  and  Intejv 

mediate  Shift 

Member. 


Idle  Gear. 


Reverse 
Gear. 


Low  and  Reverse  Shift  Rod. 


Fig.  255.— Sectional  View  of  Individual  Clutch  Gearset  with  Silent  Chains  Re- 
moved to  Show  Arrangement  of  Gearing. 

sprocket  in  the  interior  of  which  the  end  of  the  main  shaft  telescopes 
and  which  is  supported  by  suitable  ball  bearings.  The  countershaft 
mounted  above  the  main  shaft  carries  four  gears,  three  of  which  are 
adapted  to  use  silent  chains,  while  the  smallest  member  is  a  clash 
gear  of  the  conventional  pattern,  employed  only  to  obtain  reverse 
speed.  It  will  be  observed  that  two  gear  members  are  carried  by  ball 


The  Modern  Gasoline  Automobile  443 


bearings  at  the  center  of  the  main  shaft  in  such  a  way  that  they 
revolve  independently  of  that  member  unless  they  are  clutched  to  it 
by  the  positive  clutches  keyed  to  the  shaft. 

To  obtain  the  reverse  drive  the  large  reverse  gear  is  moved  back 
in  such  a  way  that  it  engages  the  reverse  pinion  on  the  countershaft. 
The  drive  in  this  case  is  from  the  motor  to  the  constant  drive  gear, 
forming  part  of  the  main  shaft  which  turns  the  countershaft  drive 
gear  by  means  of  a  silent  chain  which  is  not  shown  in  this  view  but 
which  can  be  very  clearly  seen  at  Fig.  254.  The  countershaft  is 
turning  in  the  same  direction  as  the  motor  and  the  spur  gears 
used  at  the  back  end  of  the  gearset  are  employed  to  reverse  the 
motion.  When  the  low  speed  is  desired  the  low  and  reverse  shift 
member  is  moved  in  such  a  manner  that  the  idle  gear  is  clutched 
to  the  shaft.  When  this  condition  obtains  the  drive  is  from  the 
motor  through  the  constant  drive  gears  and  from  the  countershaft 
by  the  low-speed  pinion  and  the  big  gear  which  has  been  clutched  to 
the  main  shaft  and  which  serves  to  drive  the  universal  joint  con- 
nected to  the  bevel  gearing  in  the  rear  axle. 

A  movement  of  the  high  or  intermediate  shift  member  will  give 
either  of  these  speeds  desired.  The  intermediate  speed  is  obtained 
in  exactly  the  same  manner  as  the  low  speed  except  that  the  gear  ratio 
is  such  that  a  higher  ratio  of  drive  is  provided,  while  the  high  speed 
or  direct  drive  is  obtained  by  locking  the  two  sections  of  the  main 
shaft  together. 

How  Sliding  Gearsets  Operate. — The  majority  of  change-speed 
gearsets  which  have  been  generally  fitted  to  automobile  service  are 
forms  of  sliding  gear  arrangements  and  may  be  divided  into  two 
main  classes.  In  progressive  sliding  gearsets  but  one  member  is 
employed  for  all  speeds  and  this  is  shifted  along  from  one  extreme 
position  to  the  other.  In  the  selective  system  it  is  possible  to  go 
into  any  one  of  the  speeds  or  gear  ratios  desired  without  passing  into 
other  speeds  and  with  but  a  limited  movement  of  the  shifting  mem- 
bers. 

The  sliding  gear  system  was  one  of  the  first  to  receive  general 
application  in  early  forms  of  motor  vehicles  arid  in  its  primitive 
condition  it  was  but  a  modification  of  the  back  gearing  used  on 
certain  classes  of  machine  tools,  such  as  lathes,  drill  presses,  etc.  One 


444 


The  Modern  Gasoline  Automobile 


of  the  advantages  of  this  type  when  compared  to  other  gear  trans- 
missions is  that  it  is  possible  to  provide  a  greater  number  of  speed 
changes  and  that  there  is  a  higher  driving  efficiency  when  on  the 
lower  ratios  because  but  two  pairs  of  gears  are  in  mesh. 

An  example  of  a  progressive  sliding  gear  transmission  is  depicted 
at  Fig.  256,  this  providing  three  forward  speed  ratios  and  one  re- 


Constant  Mesh  Gears. 


Lever. 


Low. 


Counter. 


Engine  End. 


tain  Shaft. 


Sliding  Member. 


Fig.  256. — Arrangement  of  Gears  in  Progressive  Sliding  Gearset. 

verse.  The  various  speed  ratios  are  secured  by  moving  the  sliding 
member  which  is  composed  of  two  gears  along  the  main  shaft  so 
that  it  engages  successively  the  gears  on  the  countershaft.  When 
the  sliding  member  is  in  the  position  shown,  no  gears  are  engaged 
and  no  power  can'  be  transmitted  through  the  gearset.  If  the  sliding 
member  is  moved  toward  the  right  so  that  it  engages  the  small 
pinion  under  the  reverse  gear  on  the  countershaft  a  reverse  drive 
would  be  obtained.  If  the  sliding  member  is  shifted  toward  the  left 
until  the  Jarge  gear  member  engages  with  the  low-speed  gear  on  the 
countershaft  the  lowest  forward  drive  ratio  is  obtained. 


The  Modern  Gasoline  Automobile 


445 


Continued  movement  of  the  sliding  member  toward  the  left  will 
cause  the  small  gear  to  engage  with  the  intermediate  pinion  and 
produce  a  ratio  of  drive  that  will  not  be  as  fast  as  the  direct  con- 


Countershaft 


High  and  Intermediate 
Speed  Shift  Member. 


Fig.  257. — Showing  Application  of  Two  Shifting  Members  on  Main  Shaft  of 
Selective  Sliding  Gear  Speed-Changing  Mechanism. 

nection  but  which  is  faster  than  the  slow-speed  ratio.  When  the 
sliding  member  is  moved  to  the  extreme  left  it  serves  to  lock  the 
two  portions  of  the  main  shaft  together  and  a  direct  drive  is  ob-. 


446 


The  Modern  Gasoline  Automobile 


tained.  The  power  from  the  engine  is  first  delivered  to  the  constant 
mesh  gear  which  normally  drives  the  countershaft  and  which  re- 
volves around  the  main  portion  of  the  main  shaft  which  telescopes 
into  its  interior. 

If  the  design  of  this  gearset  be  compared  to  that  outlined  at 
Fig.  257,  it  will  be  evident  that  in  the  latter  two  shifting  members 
are  employed  which  have  a  smaller  degree  of  movement  than  the 
single  member  of  the  progressive  type.  The  reason  that  the  selective 
system  is  generally  preferred  may  be  easily  understood  by  referring 
to  the  comparison  between  the  forms  as  shown  at  Fig.  258.  In  the 
progressive  sliding  gearset  which  is  shown  at  A,  the  shifting  member 


High  and  Int.  Shift  Member. 


Stifling  Member  for  all  S 


Low  and  Reverse 
Shift  Member. 


Countershaft. 


Slow. "*  Reverse* 


Direct.     Intermediate. 


Direct./  x  Slow. 

Intermediate. 


Reverse. 


Fig.  258. — Comparing  Progressive  and  Selective  Gearset  Action  to  Demonstrate 
Advantages  of  the  Latter  Form. 

is  shown  engaged  with  the  intermediate  gear  on  the  countershaft. 
If  it  is  desired  to  pass  into  the  reverse  from  this  position  the  slow 
speed  must  be  engaged  before  the  reverse  gear  can  be  reached.  The 
hand  lever  used  to  shift  the  gearing  is  moved  back  with  one  con- 
tinuous movement.  For  instance,  if  the  gearing  be  in  the  reverse 
position  and  it  is  desired  to  engage  the  direct  drive  it  will  be  neces- 
sary to  pass  the  one  shifting  member  to  the  low  speed,  past  the  in- 
termediate and  from  thence  into  the  direct  drive  position-. 

With  the  selective  gearset  which  is  depicted  at  Fig.  258,  B, 
the  plurality  of  shifting  members  provided  makes  it  possible  to  go 
into  any  speed  directly  without  passing  through  the  others.  For  in- 
stance, >the  high  and  intermediate  shift  member  is  shown  in  the 
position  at  which  the  intermediate  speed  ratio  is  obtained.  If  it  is 


The  Modern  Gasoline  Automobile  447 

desired  to  engage  the  high  speed  this  member  may  be  pushed  directly 
into  position  so  that  the  main  shaft  and  the  constant  drive  gear  are 
locked  together.  If  it  is  desired  to  go  into  reverse  a  simple  movement 
of  the  operating  or  shifting  member,  which  is  guided  by  an  H  slot 
gated  segment,  will  disengage  the  high  speed  and  throw  the  other 
shift  member  into  position  by  one  simple  movement. 

One  of  the  advantages  of  this  method  is  that  it  is  much  easier 
to  engage  the  gears  and  that  the  liability  of  injuring  the  gear  teeth 
by  injudicious  shifting  is  not  as  great  as  in  the  progressive  type. 
Another  advantage  of  the  selective  system  is  that  it  permits  a  more 
compact  construction  and  makes  possible  the  use  of  shorter  shafts 
which  are  stiffer  than  longer  ones  because  the  distance  between  points 
of  support  is  not  so  great.  Not  only  is  the  operation  much  easier 
but  it  is  possible  to  obtain  the  varying  speed  ratios  much  more 
quickly  than  with  the  progressive  system. 

The  usual  number  of  gear  ratios  provided  is  three  forward  speeds 
and  one  reverse  motion.  On  some  of  the  heavier  touring  cars  four 
forward  speeds  are  provided  and  when  this  is  done  engineers  differ 
as  to  whether  the  direct  drive  should  be  on  the  third  or  fourth  ratio. 
When  the  direct  drive  is  on  the  third  ratio  the  fourth  speed  is  ob- 
tained by  gearing  up  and  the  driving  shaft  revolves  faster  than  the 
main  shaft  of  the  engine.  When  the  fourth  speed  is  a  direct  drive 
the  crank  shaft  and  the  driving  shaft  turn  at  the  same  speed.  Those 
who  favor  the  former  method  contend  that  as  most  of  the  regular 
driving  is  done  at  a  medium  rather  than  at  an  extreme  high  speed  the 
direct  drive  on  the  third  is  preferable  to  a  direct  drive  on  the  highest 
ratio.  The  geared-up  fourth  speed  can  be  used  only  when  conditions 
are  exceptionally  favorable  to  high  speed.  If  the  highest  speed  was 
obtained  by  a  direct  drive  the  natural  tendency  of  the  motorist  would 
be  to  use  this  most,  but  there  would  be  many  conditions  where  the 
ratio  would  be  too  high  and  one  of  the  lower  gears  would  have 
to  be  used.  If  the  direct  drive  was  obtained  in  the  third  ratio  this 
would  be  employed  the  greater  part  of  the  time,  and  as  there  would 
be  less  wear  on  the  gearing  with  the  direct  drive  engaged  it  would 
be  preferable  to  use  this  as  much  as  possible. 

The  question  of  gear  ratio  to  use  depends  entirely  upon  local  con- 
ditions and  before  determining  the  ratios  of  the  gearing  in  the  speed- 


448  The  Modern  Gasoline  Automobile 

changing  mechanisms  it  is  imperative  that  a  definite  relation  be  es- 
tablished between  the  speed  of  the  driving  shaft  and  the  road  wheels. 
When  heavy  pleasure  cars  use  engines  of  moderate  power  the  gear 
reduction  is  usually  three  and  one  half  or  four  to  one,,  this  meaning 
that  when  the  gearing  is  in  the  direct  drive  the  engine  crank  shaft 
will  turn  three  and  a  half  or  four  times  to  one  revolution  of  the 
driving  wheels.  On  cars  where  the  margin  of  power  is  large  and 
where  high  speeds  are  desired  the  ratio  may  be  but  two  and  one  half 
to  one.  If  the  car  is  geared  too  low,  the"  engine  must  make  a  very 
high  number  of  revolutions  when  on  the  highest  speeds  and  use  much 
more  fuel  than  necessary.  On  the  other  hand,  if  the  driving  ratio 
is  too  high  it  will  be  necessary  to  change  gears  frequently  because 
even  moderate  grades  will  make  it  imperative  to  use  a  lower  ratio 
than  that  afforded  by  the  direct  drive. 

The  body  fitted  to  the  car  has  a  material  bearing  upon  the  gear 
ratios  provided.  The  driving  speed  that  would  be  entirely  practical 
on  a  chassis  fitted  with  a  roadster  body  would  be  much  too  high  if  a 
limousine  or  coupe  body  was  fitted  to  the  same  chassis.  If  the  car 
is  to  be  operated  in  regions  where  the  conditions  are  not  favorable, 
such  as  hilly  sections,  or  where  the  highways  are  poorly  developed,  a 
much  lower  final  drive  ratio  must  be  provided  than  where  the  roads 
are  good  and  conditions  favorable  to  higher  speeds.  The  speed 
ratios  when  the  low  gears  are  engaged  will  vary  from  ten  to  one  to 
such  extremes  as  twenty-five  to  one.  The  intermediate  speed  usually 
varies  from  five  to  one  to  ten  to  one,  and  a  third  ratio  in  a  four-speed 
gearset  may  vary  from  three  to  one  to  six  to  one,  and  in  some  gear- 
sets  it  may  have  a  value  of  seven  or  eight  to  one.  If  the  fourth 
speed  is  obtained  by  gearing  up  one  may  get  a  ratio  of  drive  as  high 
as  two  to  one,  though  when  the  direct  drive  is  on  the  fourth  speed 
it  is  seldom  higher  than  three  to  one. 

Most  of  the  sliding  gearsets  have  at  least  one  of  the  speeds  a 
direct  drive,  but, some  forms  have  been  devised  where  the  power  is 
transmitted  through  gears  at  all  ratios.  A  gearset  of  this  type, 
which  has  been  used  in  an  English  omnibus,  is  outlined  at  Fig.  259. 
This  operates  on  the  selective  principle,  but  the  drive  at  all  speeds 
is  through  gears.  Two  shifting  members  are  mounted  on  the  main 
shaft.  One  of  these  carries  two  small  gears,  the  other  has  two  larger 


The  Modern  Gasoline  Automobile 


449 


members.  When  the  highest  speed  ratio  is  desired,  the  largest  gear 
on  the  main  shaft  is  engaged  with  the  smallest  member  on  the  counter- 
shaft and  as  these  have  an  equal  number  of  teeth  the  shafts  will  turn 
at  the  same  speed.  When  the  smallest  member  on  the  main  shaft  is  en- 
gaged with  the  largest  gear  the  slowest  ratio  is  obtained.  This  method 
of  gearset  construction  is  seldom  followed  at  the  present  time  be- 


Main  Shaft. 


High  Speed  Gears. 


Drive  End. 


Countershaft. 


Fig.  259.— Three-Speed  Selective  Gearset  in  which  All  Speeds  are  Obtained  by 
Gears,  No  Direct  Lock  Being  Provided  for  High  Speed. 

cause  of  the  constant  grinding  of  the  driving  gears  at  all  speeds,  and 
a  certain  amount  of  noise  will  result  no  matter  how  carefully  the 
gears  are  fitted.  With  those  forms  of  gearsets  in  which  the  highest 
ratio  is  obtained  by  locking  the  two  parts  of  the  main  shaft  together 
there  are  no  gears  transmitting  power  except  those  in  the  rear  axle, 
and  the  operation  is  much  more  silent.  The  gearset  is  more  efficient 
because  the  power  loss  is  reduced  to  that  of  but  one  set  of  driving 
gears,  and  as  no  gears  in  the  gearset  are  under  driving  loads  there 
is  no  grinding  or  noise  when  on  the  direct  drive. 


Intermediate.  Low.  Reverse. 


Fig.  260. — Arrangement  of  Gears  and  Shafts  in  Typical  English  Three-Speed 

Selective  Gear  Box. 


Reverse. 


Low 


Main  Sliaf  t.' 


Reverse,  Low  and  Second  Speed. 


^Constant 
^^/Mesh  Gears. 


Engine  End. 


Fourth  Speed. 


High  and  Third  Speed  Shift  Member 


Fig.  261.— White  Four-Speed  Gearset  Has  Direct  Drive  on  Highest  Ratio. 

450 


The  Modern  Gasoline  Automobile 


451 


A  typical  sliding  gearset  of  the  three-speed  selective  type  is 
shown  in  section  at  Fig.  260,  and  at  iTig.  261  a  four-speed  gearset 
in  which  direct  drive  is  obtained  on  the  fourth  speed  is  outlined.  In 
the  former,  two  shifting  members  are  mounted  on  the  main  shaft, 
one  of  these  giving  the  high  and  intermediate  ratios,  while  the  other 
is  employed  for  low  and  reverse  speed.  '  But  two  shifting  members 
are  utilized  on  the  main  shaft  of  the  form  shown  at  Fig.  261.  One 
of  these  acts  progressively  to  give  the  reverse,  low,  and  second-speed 
ratios,  while  the  other  gives  the  third  and  fourth  speeds. 


Selecting  Rods. 


Clutch. 


Fourth 
Speed  Gears. 


Countershaft 


Fig.  262. — Winton  Four-Speed  Gearset  Provides  Direct  Drive  on  Third  Speed 
and  Gears  Up  for  Highest  on  Fourth-Speed  Ratio. 

A  four-speed  gearset  in  which  three  shifting  members  are  used 
and  in  which  a  geared-up  drive  is  obtained  on  the  fourth  speed  and 
a  direct  connection  on  third  is  shown  at  Fig.  262.  In  this  the  clutch 
is  mounted  at  the  forward  end  of  the  gearset  in  a  case  of  its  own 
and  is  a  multiple-disk  type.  The  member  shifted  by  the  center  se- 
lective rod  gives  the  second  and  third  speeds,  while  that  moved  by 


Motor. 


Motor. 


Clutch. 


Gearset. 


Fig.  263. — Conventional  Methods  of  Installing  Gearsets  in  Chassis.  A — Com- 
bined with  Engine  to  Form  Unit  Power  Plant.  B — Fitted  as  an  Individual 
Unit  Back  of  Engine.  C— Combined  with  Rear  Axle,  D— Mounted  at 
Front  End  of  Driving  Shaft  Housing. 

452 


The  Modern  Gasoline  Automobile 


453 


the  inner  rod  gives  the  reverse  and  first  speed.  The  geared-up  drive 
or  fourth  speed  is  ohtained  by  shifting  the  outer  selective  rod  and 
bringing  the  smallest  gear  on  the  main  shaft  in  mesh  with  the  largest 
gear  on  the  countershaft. 

An  important  factor  in  gearset  design  is  the  method  of  locating 
it  in  the  frame.  The  various  systems  of  gearset  mounting  in  com- 
mon use  are  shown  at  Fig.  263.  In  that  depicted  at  A  the  clutch 
and  gearset  form  a  unit  with  the  power  plant.  The  advantage  of 


'Clutch  Case. 

—Flywheel. 


Main  Shaft. 


Drive  End. 


Gear  Case. 


Fig.  264. — Clutch  and  Gearset  Portion  of  Unit  Power  Plant  Showing  Positive 
Alignment  Between  Clutch  and  Gearset  Main  Shaft. 

this  method  of  mounting  is  that  it  makes  a  very  compact  power-gen- 
erating and  speed-changing  unit  and  there  will  be  no  liability  of  lost 
alignment  between  the  engine  and  gearset.  At  B  the  gearset  is 
a  separate  member  installed  back  of  the  motor  just  under  the  front 
floor  boards,  and  when  mounted  in  this  manner  it  may  be  attached 
directly  to  the  main  frame  side  members  or  to  a  subframe  formed 
by  cross  members  which  have  been  provided  for  the  purpose.  In  the 
design  outlined  at  C  the  gearset  is  a  unit  with  the  rear  axle,  and  the 
same  argument  in  favor  of  mounting  applies  as  when  it  forms  part 


454 


The  Modern  Gasoline  Automobile 


of  the  unit  power  plant  except  that  in  this  case  there  is  no  possibility 
of  lost  alignment  between  the  gearset  and  the  driving  gears'.  The 
method  of  installing  which  is  fourth  in  popularity  is  shown  at  D. 
In  this  the  gearset  is  carried  at  the  front  end  of  the  driving  shaft 
housing  and  is  usually  attached  to  the  frame  in  such  a  manner  that 
it  will  assist  in  taking  braking  and  driving  torque. 


Fig.  265.— Herreshoff  Unit  Power  Plant  Partially  Dismantled  to  Show  Clutch 
and  Gearset  Construction. 

The  methods  qf  combining  the  gearset  with  the  clutch  case  and 
power  plant  are  shown  at  Figs.  264  and  265.  In  the  former  con- 
struction the  engine  is  shown  detached  for  convenience,,  but  the 
clutch  case  is  a  continuation  of  the  engine  bed.  At  Fig.  265  the 
gearset  is  shown  detached  from  the  power  plant  in  order  to  demon- 
strate that- the  clutch  may  be  easily  reached  when  desired.  When  the 
parts  shown  are  assembled  to  form  a  unit  the  flange  at  the  front  end 


The  Modern  Gasoline  Automobile 


455 


of  the  gearset  case  is  attached  to  that  at  the  back  end  of  the  engine 
bed  by  means  of  bolts  and  the  two  then  form  a  cover  for  the  fly  wheel 
and  multiple-disk  clutch  which  it  carries. 

When  side-chain  drive  is  provided,  as  is  often  the  case  in  motor 
trucks,  the  gearset  sometimes  forms  part  of  the  countershaft  as- 
sembly. One  of  these  designs  is  shown  at  Fig.  266,  this  illustrating 
the  general  arrangement  of  parts,  while  more  specific  details  of  con- 
struction are  outlined  at  Fig.  267.  The  construction  is  exactly  the 
same  as  though  the  countershaft  assembly  was  employed  as  a  live 
rear  axle  with  shaft  drive.  The  only  difference  is  that  the  ends 
of  the  live  axle  shaft  are  provided  with  driving  sprockets  instead  of 


Gearcase. 


.Change  Speed  Gearing. 
Bevel  Driving  Gears. 


Sprocket. 
Brake  Drum. 


-Driving  Sprocket. 


Fig.  266.— Change-Speed  Gearing  Combined  with  Countershaft  for  Side-Chain 

Drive. 

wheel  hubs.  At  Fig.  267  the  arrangement  of  the  three-speed  selective 
gearset  and  the  manner  in  which  the  bevel-driving  gears  mesh  is 
clearly  shown.  The  small  driving  pinion  is  attached  directly  to  the 
main  shaft  extension  and  there  is  but  little  possibility  of  losing  align- 
ment under  load.  The  shafts  of  the  transmission  gear  are  mounted 
on  ball  bearings  while  the  differential  and  axles  are  mounted  on 


456 


The  Modern  Gasoline  Automobile 


457 


roller  bearings.  The  drive  sprockets  carry  pressed  steel  brake  drums 
to  which  large  external  constricting  brake  bands  are  applied.  These 
serve  as  "  running  "  or  service  brakes  to  arrest  vehicle  motion  through 
the  medium  of  the  driving  chains  which  connect  the  small  sprockets 
with  the  larger  members  on  the  wheels. 

An  unconventional  form  of  rear  axle  and  gearset  combination  is 
shown  at  Fig.  268,  while  the  conventional  arrangement  is  depicted  at 


Driving  Shaft. 


Bevel  Driving  Gear, 
Differential  Gear. 


Taper  Roller  Bearing. 

Bevel  Drive  Pinion. 

Gear  Shaft. 

Axle  Shaft. 


Axle  Shaft. 


Gear  Housing. 


Countershaft. 


Fig.  268. — Unconventional  Arrangement  of  Three-Speed  Selective  Sliding  Gear- 
set  in  Combination  with  Rear  Axle  to  Secure  More  Compact  Construction 
by  Housing  Change  Speed  and  Driving  Gear  in  Common  Use. 

Fig.  269.  In  the  former  the  main  shaft  of  the  gearset  is  in  the 
form  of  a  quill  or  tube  which  surrounds  one  of  the  axle  shafts  and 
the  countershaft  is  a  separate  member  carried  directly  in  back  of  the 
main  shaft.  When  on  the  direct  drive  the  high-speed  shift  member 
is  moved  toward  the  left  and  locks  the  differential  gear  case  firmly 
to  the  quill,  which  acts  as  the  main  shaft.  When  the  parts  are  locked 
together  in  this  manner  a  direct  drive  is  obtained.  The  lower  speed 


458 


The  Modern  Gasoline  Automobile  459 

ratios  are  obtained  in  the  same  manner  as  in  any  other  selective 
transmission,  the  gears  on  the  main  shaft  being  moved  to  engage 
the  corresponding  members  on  the  countershaft.  The  contention 
is  made  that  this  method  of  design  makes  for  a  more  compact  as- 
sembly as  all  parts  are  housed  in  one  casing  member. 

Most  engineers  who  favor  combining  the  rear  axle  and  the  trans- 
mission use  the  construction  outlined  at  Fig.  269.  In  this  all  parts 
are  so  clearly  shown  that  the  method  of  application  should  be  suffi- 
ciently clear  without  lengthy  description.  The  change-speed  gearing 
is  a  conventional  three-speed  and  reverse  selective  sliding  gear  type 
and  the  drive  to  the  rear  axle  is  by  the  usual  bevel-gear  connection. 
The  various  systems  of  driving  and  methods  of  manipulating  the 
speed-change  levers  will  be  considered  more  fully  in  proper  sequence. 


CHAPTEE    IX 

The  Chassis  and  Its  Components — Frame  Design  and  Construction — Typical 
Methods  of  Spring  Suspension  Outlined — Function  of  Steering  Gears — 
Steering  Gear  Forms  Denned — Front  Axle  Types — Rear  Axle  and  Driv- 
ing Means — Power  Transmission  by  Bevel  and  Worm  Gearing — Conven- 
tional Braking  Systems — Application  of  Front  Wheel  Brakes. 

THE  average  motor-car  chassis  is  composed  of  a  number  of  parts 
distinct  from  the  power  plant  and  transmission  groups.  The  im- 
portant components  are  the  axles,  the  steering  system,,  the  method 
of  power  transmission  to  the  wheels,  the  design  of  the  frame,  and  the 
spring  suspension  means.  The  frame  forms  a  connecting  link  be- 
tween the  motive  power  and  the  parts  which  serve  to  support  the 
body  and  machinery.  Formerly  frames  were  made  in  many  different 
styles  and  a  number  of  different  materials  were  utilized  in  their  con- 
struction. At  the  present  time  the  practice  has  crystallized  to  a  point 
where  certain  construction  has  been  definitely  accepted  as  the  best  and 
this  is  generally  followed  in  practically  all  forms  of  motor  cars. 

Frame  Design  and  Construction. — The  usual  arrangement  of  the 
components  of  typical  chassis  forms  is  outlined  at  Fig.  270.  The 
power  plant  and  its  accessory  groups  as  well  as  the  change-speed  gear- 
ing have  been  previously  described,  and  the  chassis  forms  outlined 
are  presented  to  show  the  two  distinct  systems  of  chassis  construction 
generally  followed.  The  arrangement  of  parts  depicted  has  become 
accepted  as  best  practice  and  practically  all  motor  cars  are  about  the 
same  in  general  design.  The  arrangement  of  the  chassis  shown  at  A 
is  the  conventional  one,  and  in  this  the  frame  which  carries  the 
operating  parts  is  mounted  above  the  axle.  In  the  form  shown  at  B 
an  underslung  frame  construction  is  used.  In  this  case  the  springs 
are  coupled  to  the  axles  but  the  frame  members  are  suspended  from 
the  springs  instead  of  being  placed  above  them  as  shown  at  A. 

The  advantages  claimed  for  the  underslung  construction  are  that 
it  is  more  stable  because  the  weight  is  carried  nearer  the  ground  and 

460 


The  Modern  Gasoline  Automobile 


461 


the  car  is  more  easy  riding  and  will  sway  less  at  high  speeds  than 
those  types  where  the  frame  is  carried  above  the  axle.  The  advantage 
of  bringing  the  center  of  gravity  close  to  the  ground  is  clearly  illus- 
trated at  Fig.  271.  At  A  the  center  of  gravity  of  a  heavy  limousine 
car  which  has  an  underslung  frame  is  at  a  point  just  above  the-  axle, 


Fig.  271. — Advantage  of  Low  Weight  Placing  and  Carrying  Center  of  Gravity 
Near  the  Ground.  A — Low  Center  of  Gravity  Makes  for  Stability. 
B— High  Center  of  Gravity  Unsafe. 

and  if  the  car  tilts  over  a  marked  degree,  a  line  drawn  from  the  center 
of  gravity  will  fall  within  the  area  of  the  base  of  support  as  repre- 
sented by  the  rectangle,  the  corners  of  which  are  at  the  contact  points 
of  the  wheels  and  the  ground.  The  center  of  gravity  of  any  body  is 
the  theoretical  point  around  which  the  weight  may  be  said  to  be 
evenly  distributed,  and  whenever  a  line  drawn  from  the  center  of 
gravity  falls  within  the  base  line  of  any  body  or  mass  it  is  in  stable 
equilibrium. 

In  the  ca&e  outlined  at  B  the  center  of  gravity  is  carried  higher 
because  the  frame  is  mounted  above  the  axle  and  conditions  may 
obtain  where  the  line  drawn  from  the  center  of  gravity  will  fall  out- 
side of  the  base  line  and  the  car  tip  over.  While  the  conditions  shown 
are  somewhat  exaggerated  they  will  serve  to  make  the  comparison 
clear  and  will  enable  the  nontechnical  reader  to  understand  the 


462  The  Modern  Gasoline  Automobile 

advantage  of  carrying  the  weight  of  the  machinery  as  near  the  ground 
as  possible  to  secure  steadiness  at  high  speeds. 

The  factor  of  carrying  the  weight  low  is  much  more  important 
in  the  case  of  cars  which  are  to  be  equipped  with  large  closed  bodies 
of  the  limousine  type.  It  must  not  be  inferred  that  it  is  not  possible 
to  carry  the  weight  low  with  the  form  of  frame  construction  defined 
at  Fig.  270,  A,,  as  in  the  case  illustrated  the  machine  weight  is  car- 
ried practically  as  near  to  the  ground  as  it  is  when  the  underslung 
frame  shown  at  B  is  employed.  The  difference  in  center  of  gravity 
of  the  whole  machine  is  evident  only  when  the  body  is  fitted  and  it 
will  be  carried  considerably  lower  with  the  underslung  frame  than  hi 
the  one  where  the  frame  members  are  mounted  above  the  axles. 

Materials  Employed  in  Frame  Construction. — The  first  motor  cars 
were  based  somewhat  on  experience  obtained  in  bicycle  construction 
and  had  frames  made  of  steel  tubing.  This  material  was  not  as 
suitable  for  motor-car  frames  as  it  had  been  for  the  lighter  two- 
wheeled  vehicles  because  the  multiplicity  of  brazed  joints  necessary 
made  the  frame  quite  a  costly  proposition.  Then  again  the  round 
section  of  the  tubing  did  not  offer  as  easy  means  of  attaching  the 
engine  and  transmission  units  as  do  those  frames  which  are  com- 
posed of  members  having  a  rectangular  section.  Tubing  is  used 
only  in  subframe  work,  at  the  present  time  notably  in  the  Flanders 
light  four-cylinder  car  and  some  of  the  Lozier  models. 

Following  the  use  of  the  tubing,  automobile  builders  used  angle 
iron  and  other  structural  shapes  available  on  the  open  market.  Other 
makers  used  wooden  frame  members,  but  at  the  present  time  one 
rarely  finds  either  structural  iron  or  wood  used  in  pleasure  cars, 
though  both  of  these  materials  have  been  applied  to  some  extent  in 
motor-truck  construction.  Some  makers,  notably  the  Franklin  Com- 
pany, employ  frames  which  are  made  of  laminations  of  specially 
seasoned  and  strong  wood.  The  majority  of  manufacturers,  however, 
favor  the  use  of  pressed  steel  forms  which  are  not  only  light  and 
strong  but  which  have  a  degree  of  flexibility  which  is  very  desirable 
and  which  is  not  easily  obtained  with  the  various  structural  shapes 
in  iron. 

Frames,  may  be  divided  into  five  main  classes,  as  follows:  Those 
in  which  wood  only  is  used,  forms  utilizing  pressed  steel  construction^ 


The  Modern  Gasoline  Automobile 


463 


types  employing  steel  tubes,  frames  built  up  of  iron  structural  shapes, 
and  combination  frames  where  two  or  more  different  methods  of 
construction  may  be  combined.  For  instance,  it  is  possible  to  ree'n- 
force  a  wooden  frame  side  member  with  a  strip  of  steel  or  iron,  or  at 
the  other  hand  some  makers  sometimes  fill  the  channel  of  a  pressed 
steel  frame  with  wood  to  strengthen  it.  Each  of  these  main  divi- 
sions might  be  again  divided.  For  instance,  wood  frames  may  be 
made  of  a  solid  strip  or  beam  or  may  be  composed  of  vertical  or 
horizontal  laminations.  Pressed  steel  may  be  made  into  channels, 
angles,  or  modifications  of  these,  while  frames  composed  of  tubing 
may  be  square,  rectangular,  or  round  section.  The  various  structural 
shapes  may  be  utilized  in  the  form  of  plate,  angles,  T  rail  sections, 
and  I  beams. 

A  typical  pressed  steel  frame  is  shown  at  Fig.  272  and  this  is  the 
type  which  is  very  generally  employed.     The  frame-side  members  are 


Running  Board  Irons 


Fig.    272.— Conventional    Form    of    Pressed    Steel    Automobile    Frame    with 
Cambered  Side  Members. 

two  pressed  steel  forms  cambered  at  the  front  ends  and  joined  to- 
gether by  a  series  of  three  cross  braces.  The  front  one  serves  as  a 
radiator  support,  that  in  the  center  provides  anchorage  for  the  torque 
tube  of  the  axle,  while  the  rear  cross  member  projects  on  either  side  of 
the  frame  and  .provides  a  point  of  anchorage  for  the  rear  support- 
ing springs.  iThe  object  of  cambering  the  frame  members  in  front 
is  to  provide  a  greater  angle  of  operation  for  the  front  wheels  and  to 


464 


The  Modern  Gasoline  Automobile 


permit  turning  on  curves  of  smaller  radius  than  would  be  possible 
if  the  frame  members  were  straight  and  movement  of  the  wheels 
limited  thereby. 

In  some  frame  constructions  where  semi-elliptic  springs  are  used 
at  the  rear  end  as  well  as  the  front  of  the  car,  the  frame  is  some- 
times raised  at  a  point  directly  over  the  axle,  as  shown  at  Fig.  273,  A. 
Often  a  double -drop  is  provided  in  the  frame  side,  as  shown  at  Fig. 
273,  B.  In  this  construction  the  frame  side  is  straight  to  a  point 


Fig.  273.— Frame  Forms  Having  Raised  Side  Members.     A— Frame  Side  Raised 
Over  Axle.     B — Framework  with  Drop  Side  Member. 

about  half  the  length  of  the  chassis,  then  it  drops  and  when  it  reaches 
the  axle  it  raises  again  to  allow  for  movement  of  the  axle.  The  ob- 
ject of  dropping  the  frame  is  to  provide  a  slightly  lower  floor  boar^d 
placing  than  would  be  possible  if  the  body  was  carried  at  one  level. 
The  rear  upsweep,  by  raising  the  back  end  of  the  frame,  enables  the 
axle  to  be  carried  in  a  position  that  will  permit  a  nearly  straight 
line  drive.  It  will  also  bring  the  running  board  of  the  car  closer 
to  the  ground,  which  makes  the  body  more  accessible,  and  it  lowers 
the  center  of  gravity  as  well.  At  the  same  time  sufficient  space  is 
provided  between  the  raised  rear  end  and  the  axle  to  permit  of  using 
springs  which  will  be  adequate  to  support  the  weight,  of  the  mechan- 
ism and  body  and  yet  permit  these  to  have  a  considerable  radius  of 
movement  and  make  for  much  easier  riding. 


The  Modern  Gasoline  Automobile  465 

By  bringing  the  lowest  level  at  a  point  between  the  front  and 
rear  it  is  possible  to  carry  the  body  low  and  at  the  same  time  support 
the  engine  and  transmission  at  a  sufficient  height  above  the  ground 
to  insure  ample  clearance  between  the  bottom  of  the  motor  and  the 
surface  of  the  roadway.  The  advantage  of  the  pressed  steel  frame 
over  the  other  forms  is  that  it  is  a  very  easy  type  to  make  and  very 
cheap  after  the  forming  dies  have  been  made.  It  lends  itself  read- 
ily to  designs  where  it  would  not  be  possible  to  use  the  wood  frame 
because  of  the  serious  diminution  of  strength  if  wood  is  bent  in  any 
way  that  will  distort  the  grain. 

Suspension  of  Motor  Vehicles. — One  of  the  most  important  prob- 
lems in  connection  with  chassis  designing  is  that  of  the  supporting 
members  which  join  the  frame  to  the  axles  and  which  are  depended 
upon  to  absorb  much  of  the  shock  and  jar  incidental  to  motor-car 
operation.  The  importance  of  the  springs  and  the  part  they  play 
in  promoting  the  comfort  of  the  passengers,  the  durability  of  the 
machinery,  and  economical  application  of  power  are  but  little  appre- 
ciated by  the  majority  of  motorists.  One  point  that  has  made  it 
difficult  for  the  automobile  designer  to  evolve  spring  types  which 
were  entirely  satisfactory  was  the  paucity  of  data  regarding  spring 
action  of  high-speed  vehicles.  The  forms  of  springs  that  were  used 
on  wagons  and  carriages  were  studied,  but  when  these  were 
applied  to  motor  cars  which  had  much  greater  speed  than  the  simpler 
vehicles  the  problem  assumed  a  new  aspect.  While  the  horse-drawn 
vehicle  operates  on  rough  roads  the  speeds  are  comparatively  low, 
and  the  roughness  of  the  roads  is  hot  such  an  important  factor  as  it  is 
in  the  design  of  automobile  springs.  Eailway  cars  were  studied  in 
the  hope  of  finding  a  solution.  Here  the  conditions  are  reversed,  and 
while  they  operate  at  high  speeds  they  run  on  comparatively  level- 
steel  rails  and  the  conditions  of  operation  make  the  problem  of  spring 
suspension  one  that  is  not  difficult. 

One  point  greatly  in  favor  of  the  motor  car  is  that  for  the  most 
part  these  are  mounted  on  pneumatic-  or  air-filled  tires  and  these 
have  valuable  cushioning  properties  in  themselves  and  are  of  material 
value  in  solving  the  problem  of  spring  suspension.  It  is  very  difficult 
to  combine  both  strength  and  resiliency  in  springs,  as  if  these  are 
made  light  and  flexible  they  are  not  likely  to  be  strong.  A  vehicle 


466  The  Modern  Gasoline  Automobile 

that  might  be  very  easy  riding  on  good  roads  would  have  too  much 
spring  movement  if  the  springs  were  lacking  in  strength  when  oper- 
ated on  rougher  road  beds.  At  the  other  hand,  if  springs  are  made 
stiff  to  take  care  of  severe  conditions  they  will  be  hard  acting  when 
used  on  smooth  roads. 

Another  factor  which  makes  it  difficult  to  select  the  proper 
springs  is  the  variation  in  weight  carried.  When  an  engineer  de- 
signs a  five-passenger  touring  car  he  must  provide  springs  of  adequate 
strength  to  take  care  of  the  car  when  it  carries  its  full  complement. 
If  but  two  passengers  are  carried  the  car  will  be  stiff er  riding  than 
when  the  weight  of  five  persons  must  be  supported. 

An  added  point  that  makes  it  difficult  to  select  springs  for  auto- 
mobile suspension  except  by  experiment  is  that  the  propelling  force 
forms  part  of  the  conveyance  and  power  must  be  transmitted  from 
the  source  mounted  on  the  frame  to  the  wheels  resting  on  the  ground. 
As  the  frame  is  suspended  on  more  or  less  flexible  members  and 
moves  in  various  directions,,  the  degree  of  movement  must  be  limited 
so  there  will  be  no  excessive  strain  imposed  on  the  transmission 
mechanism.  Ease  of  riding  is  largely  determined  by  the  radius  of 
movement  or  upward  throw  of  the  body,,  and  the  object  with  any  kind 
of  spring  suspension  is  to  reduce  the  up  and.  down  movement  to  as 
low  a  point  as  possible  without  actually  retarding  the  vibrations. 
Rapid  vibration  of  the  springs  will  cause  discomfort  and  will  affect 
to  a  considerable  degree  various  parts  of  the  chassis  which  connect 
the  frame  to  the  axle,  such  as  radius  rods,  steering  connections,  torque 
members,  and  driving  means. 

Of  the  various  forms  of  springs  it  is  possible  to  use  the  laminated 
leaf  spring  is  that  which  has  been  generally  applied  on  automo- 
biles just  as  its  use  has  become  universal  on  horse-drawn  conveyances. 
The  great  value  of  the  laminated  leaf  spring  is  that  its  capacity 
can  be  varied  by  changing  the  number  of  plates  or  leaves  used  and 
almost  any  desired  degree  of  resiliency  can  be  obtained  by  varying 
the  thickness,  grade  of  material,  and  width  of  the  plates  of  which 
the  spring  is  composed. 

Design  of  Leaf  Springs. — The  leaf  springs  used  for  the  suspension 
of  roads  vehicles  consist  of  several  layers  of  steel  plates  so  shaped 
that  when  laid  together  they  form  superimposed  arcs  of  as  many 


The  Modern  Gasoline  Automobile 


467 


circles  as  there  are  leaves.  The  spring  effect  is  obtained  by  the  elas- 
ticity of  the  metal  used  which  is  increased  in  value  by  a  process  of 
heat  treatment  known  as  tempering.  The  leaves  are  usually  gradu- 
ated in  thickness,  being  thicker  at  the  center  and  tapering  from  the 
center  to  the  ends. 

The  reason  for  following  a  common  line  or  arc  when  a  spring 
is  composed  of  more  than  one  leaf  is  that  as  all  of  the  leaves  are  de- 
flected at  once  by  the  load  and  as  the  tendency  is  to  straighten  out 
the  curved  member,  they  should  slide  upon  one  another  when  alter- 
ing their  shape  in  such  a  manner  that  they  will  always  be  in  contact 
with  the  neighboring  leaf  at  all  points.  If  the  curvature  of  the 
leaves  differed  appreciably  the  tendency  of  the  plates  under  load 
would  be  to  straighten  out  and  separate  and  the  load  would  only  be 
carried  on  those  members  which  were  in  contact  at  all  points.  This 
would  be  undesirable  because  it  would  cause  a  loss  of  spring  action 
would  also  result  in  frequent -breakage. 


Fig.  274. — Springs  Usually  Employed  for  Supporting  Motor-Car  Frames  and 
Horse-Drawn  Vehicle  Bodies. 

The  common  forms  of  springs  which  have  been  used  for  supporting 
motor-car  frames  are  shown  at  Fig.  274.  That  at  A  is  a  full  elliptic 
type  and  consists  of  two  semi-elliptic  spring  members  hinged  together 
at  their  ends.  The  semi-elliptic  type,  which  is  half  of  a  full  elliptic 


468 


The  Modern  Gasoline  Automobile 


spring,  is  shown  at  B.  The  spring  illustrated  at  C  is  a  three  quarter 
elliptic  form  used  for  suspending  the  front  end  of  some  types  of 
cars.  The  scroll  elliptic  spring  depicted  at  D  is  a  modification  of  the 
full  type,  but  it  is  somewhat  more  flexible  because  the  lower  member 
is  fastened  to  the  upper  by  means  of  shackles  which  permit  more 
movement  than  the  rigid  bolt  and  eye  connecting  the  members  of 
form  A.  The  side  spring  depicted  at  E  is  a  modification  of  the 
side  spring  commonly  fitted  to  Concord  buggies,  and  while  it  has 
received  some  application  on  earlier  forms  of  automobiles  it  is  not 
used  at  the  present  time.  The  form  shown  at  F  is  a  three  quarter 
scroll  elliptic  member  which  is  very  widely  used  at  the  present  time 
for  rear  suspension  of  motor  cars,  especially  in  those  chassis  having 
upswept  rear  ends. 

The  application  of  the  spring  forms  previously  considered  to  the 
front  end  of  motor-car  frames  is  outlined  at  Fig.  275.     The  views  at 


Fig.  275. — Spring  Suspension  Means  for  Front  Ends  of  Motor-Car  Frames. 
A— Semi-Elliptic.  B — Full  Elliptic  of  Franklin  Car.  C— Single  Cross 
Spring  of  Ford  Design. 

Fig.  276  show  various  spring  combinations  used  for  rear-end  suspen- 
sion. The  common  method  of  supporting  the  front  end  is  shown  at 
Fig.  275s,  A,  and  is  used  on  the  greater  proportion  of  motor  cars.  Of 
the  rear  suspensions  that  shown  at  Fig.  276,  D,  is  popular  on  heavy 


The  Modern  Gasoline  Automobile 


469 


vehicles,  while  the  full  elliptic  depicted  at  C  and  the  three  quarter 
scroll  elliptic  outlined  at  E  also  receive  general  application.  The 
semi-elliptic  spring  is  not  as  easy  riding  as  the  other  forms  unless  it  is 
made  very  long  and  composed  of  but  a  few  leaves.  The  various  full 


Fig.  276. — Spring  Suspensions  for  Rear  Ends  of  Motor-Car  Chassis.  A — Sin- 
gle Elliptic  Cross  Spring  of  Ford  Cars.  £ — Semi-elliptic  Side  Member. 
C— Rear  Support  by  Full  Elliptic  Spring.  D — Platform  Spring  Con- 
struction. E — Three  Quarter  Elliptic  Application. 

and  three  quarter  elliptic  forms  are  much  more  flexible  than  a  semi- 
elliptic  of  the  same  length  and  are  more  generally  used  for  rear  sus- 
pension where  a  greater  degree  of  movement  is  desirable  than  at  the 
front  end. 

When  an  automobile  chassis  is  suspended  on  springs  the  frame 
will  move  in  various  directions.  There  is  a  certain  amount  of  for- 
ward and  backward  end  throw,  an  element  of  side  sway  and  the 
up  and  down  motion  caused  by  the  deflection  and  recoil  of  the  spring. 
The  object  of  an  efficient  spring  suspension  should  be  to  minimize  the 
end  throw  and  side  sway  as  much  as  possible  and  yet  preserve  the 
freedom  of  movement  of  the  spring.  It  is  for  this  reason  that  the 
serni-elliptic  form  is  so  popular  for  front  suspension.  It  is  a  stiffer 
member  than  the  others  and  is  better  adapted  to  carry  the  weight  of 
the  power  plant  without  side  away  and  to  keep  the  front  axle  in  that 


470  The  Modern  Gasoline  Automobile 

relation  with  the  steering  mechanism  necessary  to  secure  the  best 
action. 

In  general  the  methods  of  suspension  employed  by  automobile  de- 
signers follow  closely  those  that  have  been  used  for  a  number  of  years 
by  manufacturers  of  horse-drawn  vehicles.  When  elliptic  or  semi- 
elliptic  springs  of  the  ordinary  description  are  used  one  will  see  that 
in  most  light  horse-drawn  carriages  but  two  are  employed,  one  being 
placed  over  each  axle  and  parallel  with  it.  In  motor  cars  one  seldom 
finds  a  single  spring  used  for  suspension  at  both  ends.  Usually  if 
one  spring  is  placed  in  this  manner  over  one  of  the  axles  there  are 
generally  two  arranged  in  the  conventional  manner  over  the  other 
axle  to  provide  a  three-point  support.  A  notable  exception  is  the 
Ford  car  which  employs  a  single  cross  spring  at  each  end  of  the  frame. 

When  only  one  spring  is  used  in  this  manner  radius  or  distance 
rods  are  required  to  maintain  a  fixed  distance  between  the  axle  and 
the  frame  at  the  front  axle,  and  more  substantial  members  of  the  same 
character  which  will  have  to  take  the  driving  torque  effect  as  well  as 
the  braking  stresses  will  be  required  for  the  rear  end.  This  makes 
two  sets  of  radius  rods  necessary  on  each  car.  Most  automobile  de- 
signers favor  the  use  of  two  semi-elliptic  springs  at  the  front  end  be- 
cause with  these  there  will  be  no  need  of  using  radius  rods,  as  the 
springs  are  capable  of  maintaining  the  proper  relation  between  the 
axle  and  the  frame  as  well  as  resist  the  pushing  or  pulling  effect  due 
to  traction,  which  would  otherwise  have  to  be  taken  by  radius  rods. 

With  practically  all  forms  of  rear  suspension,  especially  in  those 
which  utilize  the  elliptical  forms  of  springs,  the  inevitable  forward 
throw  makes  the  use  of  radius  rods  imperative.  It  is  necessary  that 
the  proper  distance  be  maintained  between  the  motor  mounted  on  the 
frame  and  the  rear  axle  where  the  power  is  applied  to  the  wheels. 
The  amount  of  play  permissible  is  governed  entirely  by  the  char- 
acter of  the  driving  system  and  with  some  forms  there  can  be  more 
latitude  of  movement  than  possible  with  others.  In  nearly  all  cases, 
however,  it  is  essential  that  very  nearly  a  fixed  distance  be  maintained, 
or  there  will  be  injurious  stresses  on  the  sprockets,  chains,  universal 
joints,  or  gears  with  attendant  loss  of  power. 

A  factor  that  has  become  very  important  is  the  selection  of  suitable 
alloy  steels  for  the  construction  of  the  springs.  The  rapid  develop- 


The  Modern  Gasoline  Automobile  471 

ment  of  high-powered  automobiles  which  are  capable  of  extremely 
high  speeds  had  made  the  development  of  more  resisting  and  elastic 
steels  imperative,  as  the  open  hearth  metal  of  standard  analysis  used 
in  the  manufacture  of  carriage  springs  would  not  make  satisfactory 
supporting  members  under  the  severe  conditions  imposed  by  the  mod- 
ern automobile.  For  this  reason,  various  alloy  steels,  such  as  vana- 
dium steel  and  mixtures  of  iron,  carbon,  chromium,  and  nickel  have 
been  developed  especially  for  fabrication  into  springs. 

Among  the  other  functions  of  springs  they  reduce  to  a  certain 
extent  the  traction  resistance.  When  the  driving  wheels  meet  ob- 
stacles the  shock  produced  depends  upon  the  inertia  of  the  axle  and 
that  of  the  wheel  which  comes  into  contact  with  the  impeding  sub- 
stance plus  the  resistance  of  the  springs,  which  factor  varies  with 
the  elasticity  and  design.  If  the  springs  are  not  sufficiently  resilient 
the  shock  will  lift  a  portion  of  the  car  as  well  as  the  wheel  and  axle, 
whereas  if  elastic  members  are  employed  only  the  axle  and  spring 
will  be  affected.  It  is  patent  that  more  power  is  required  to  sur- 
mount obstacles  when  stiff  springs  are  employed,  and  part  of  the 
power  delivered  by  the  engine  which  might  be  used  to  better  advan1 
tage  in  propelling  the  car  is  absorbed  in  overcoming  the  obstacle. 

The  attachment  of  springs  to  the  fr^me  and  axle  is  a  phase  of 
the  suspension  problem  that  is  important.  The  front  end  of  the 
front  springs  is  usually  pivoted  directly  to  the  frame  in  spring 
horns  forming  a  portion  of  the  frame-side  member.  The  free  end 
of  the  spring  is  connected  to  the  frame  by  a  shackle  to  allow  the 
necessary  motion.  The  rear  springs  are  usually  attached  to  the 
frame  in  a  different  manner  than  the  front  member  because  to  secure 
maximum  efficiency  the  rear  springs  should  be  called  upon  only  to 
support  the  load,  and  they  should  be  relieved  of  all  traction  and 
torsion  forces  by  suitable  torque  members  or  radius  rods.  If  springs 
of  the  semi-elliptic  type  are  used  it  is  advisable  to  double-shackle  them, 
whereas  full  elliptic  forms  should  be  attached  to  the  frame  by  some 
sort  of  a  swivel  joint  in  order  to  allow  the  necessary  motion. 

The  method  of  fastening  the  springs  to  the  axle  is  by  means  of 
clips  very  similar  to  those  that  are  used  in  carriage  construction,  but 
they  are  usually  heavier  and  of  better  material.  The  spring  rests 
upon  a  piece  of  leather  or  wood  placed  between  it  and  the  supporting 


472 


The  Modern  Gasoline  Automobile 


pad  on  the  axle  and  this  material  is  usually  curved  enough  to  con- 
form with  the  arc  of  curvature  of  the  spring.  This  cushion  is 
interposed  between  the  two  elements  for  two  reasons,  one  of  these 
being  to  avoid  the  strain  which  would  be  imposed  upon  the  spring  if 
attempt  was  made  to  attach  it  directly  to  the  flat  or  slightly  curved 
spring  pad  on  the  axle.  The  other  reason  is  that  the  cushion  provides 
a  more  rigid  fastening  because  there  is  a  certain  amount  of  friction 


pring 


Friction 
Adjusting  Nut 


Friction  Washers 


Fig.  277. — Unconventional  Spring  Suspensions.  A— Double  Semi-Elliptic  Used 
on  Winton  Cars.  B — Coil  Spring  and  Shock  Absorber  Combination  of 
Liberty-Brush  Runabouts. 

between  the  spring  and  the  wood  or  leather  piece  which  prevents 
slipping  of  the  fastening.  Authorities  agree  that  springs  should 
never  be  fastened  by  means  of  bolts  passing  through  the  leaves,  as 
this  will  make  a  weak  place  in  the  spring  which  may  break  if 
stressed  unduly  at  this  point. 

Some  manufacturers  use  distinctive  forms  of  springs  developed 


The  Modern  Gasoline  Automobile  473 

solely  for  use  on  their  product.  The  spring  shown  at  Fig.  277,  A, 
is  that  employed  on  some  models  of  the  Winton  cars  and  is  a  com- 
pound form  which  consists  of  two  parts  which  are  virtually  separate 
and  distinct  semi-elliptic  springs.  These  are  shackled  up  in  such  a 
manner  that  when  the  loads  are  light  but  one  portion  of  the  spring 
is  used,  though  when  the  car  is  fully  loaded  both  sections  of  the  spring 
are  brought  in  action.  It  is  claimed  that  this  method  of  spring  con- 
struction permits  easy  riding  under  all  varying  conditions  of  load 
or  road  surface,  as  the  strength  or  resiliency  of  the  springs  is  governed 
entirely  by  the  demands  made  upon  it.  When  conditions  of  operation 
are  severe  the  spring  strength  is  augmented  proportionately,  and  it 
becomes  more  resilient  as  the  load  is  decreased. 

The  method  of  suspension  employed  on  the  Brush  runabout  is 
outlined  at  Fig.  277,  B.  This  is  distinctive  inasmuch  as  it  is  the 
only  motor  vehicle  produced  in  large  quantities  or  in  a  commercial 
way  which  employs  helical  coil  springs  under  tension  to  support  the 
load.  It  will  be  noted  that  a  combined  shock-absorbing  and  radius- 
rod  device  is  essential.  Ths  method,  while  extremely  efficient,  ap- 
pears rather  unconventional  and  is  regarded  as  a  "  freak  "  design  by 
most  engineers.  The  construction  is  clearly  outlined  in  the  illustra- 
tion and  four  such  springs  are  employed,  one  at  each  corner  of  the 
frame. 

How  Automobiles  are  Steered. — The  problem  of  steering  the  motor 
car  is  a  somewhat  different  one  than  that  of  directing  a  horse-drawn 
vehicle  because  in  the  animal-drawn  conveyance  the  shafts  which  are 
attached  to  the  front  axle  are  used  to  turn  the  vehicle  as  well  as  to 
pull  it  along.  The  front  axle  is  usually  pivoted  at  a  central  point 
and  turns  on  a  fifth-wheel  arrangement,  as  shown  at  Fig.  278,  A. 
Wlien  it  is  desired  to  turn  in  either  direction  the  animal  is  guided 
by  the  reins  and  the  axle  is  turned  at  an  angle  to  the  body  sufficient 
to  allow  the  vehicle  to  describe  a  curve  as  shown  by  the  dotted  lines. 
When  turning  sharply  or  in  a  narrow  thoroughfare  the  construction 
is  usually  such  that  the  front  wheels  may  swing  under  the  carriage 
body  in  such  a  way  that  the  front  axle  may  be  parallel  with  the  body 
side  members  or  at  right  angles  to  the  rear  axle  under  extreme  condi- 
tions. The  stability  of  the  carriage  would  be  very  poor  if  it  was  not  for 
the  bracing  effect  derived  from  the  horses'  weight  between  the  shafts. 


474 


The  Modern  Gasoline  Automobile 


In  most  motor  vehicles  the  propulsive  force  is  applied  to  the  rear 
wheels  and  the  structure  is  pushed  from  behind  instead  of  being 
pulled,  as  is  the  case  with  a  horse-drawn  conveyance.  Obviously,  it 
would  not  be  practical  to  turn  the  entire  axle  under  the  car  because 
if  it  described  a  too  acute  angle  when  the  car  was  driven  at  high 


Fig.  278.— Methods  of  Steering  Vehicles  Outlined.  A— Horse-Drawn  Wagon 
Directed  by  Swinging  Axle.  B — Motor  Car  Steered  by  Movable  Wheels 
on  Fixed  Axle. 

speed  it  would  be  extremely  difficult  to  control  the  vehicle.  This  was 
very  ingeniously  overcome  by  an  engineer  named  Ackerman,  who  de- 
vised the  pivoted  axle  which  is  commonly  accepted  as  the  proper 
method  of.  steering  automobiles. 

This  consisted  of  a  fixed  axle  member,,  as  shown  at  Fig.  278,,  B, 


The  Modern  Gasoline  Automobile  475 

* 

which  was  attached  to  a  frame  by  suitable  springs  or  other  means  in 
such  a  way  that  it  could  only  move  in  a  vertical  direction  under  the 
influence  of  road  irregularity.  The  wheels  are  mounted  on  spindles 
carried  in  a  yoke  at  each  end  of  the  axle,  and  wfyen  it  is  desired  to 
turn  an  automobile  only  the  wheels  are  turned  instead  of  moving  the 
entire  axle  assembly  as  is  the  case  in  a  horse-drawn  vehicle. 

In  order  to  actuate  the  steering  knuckles,  suitable  mechanism  that 
will  be  easily  operated  must  be  placed  convenient  to  the  driver.  The 
earlier  forms  of  automobiles  were  provided  with  forms  of  tillers  very 
similar  to  those  employed  in  controlling  boats,  but  while  these  simple 
levers  gave  a  certain  degree  of  satisfaction  on  light  cars  operated  at 
slow  speeds,  the  development  of  the  higher-speed  vehicles  made  neces- 
sary more  easily  handled  and  positive  forms  of  steering  gears.  The 
disadvantages  of  the  tiller  are  that  it  may  be  whipped  out  of  the 
operator's  hands  by  road  irregularities,  and  it  is  very  tiresome  to  hold 
because  of  the  continual  vibration. 

With  the  modern  forms  of  wheel-steering  devices  the  hands  are 
always  in  ^an  easy  position,  the  wheels  may  be  readily  operated  and 
because  of  the  elimination  of  vibration  by  the  feature  of  irreversibility 
provided  by  most  steering  gears  of  conventional  construction,  no  road 
shock  can  loosen  the  grip  of  the  driver,  nor  is  he  fatigued  by  con- 
tinued movement  of  the  wheel. 

Steering  gears  are  made  in  a  variety  of  forms  and  all  types  have 
their  adherents.  The  accepted  construction  is  clearly  illustrated  at 
Fig.  279,  A.  In  this  the  steering  wheel  is  attached  to  a  rod  which 
carries  a  worm  at  its  lower  end.  This  worm  meshes  with  a  worm 
gear  to  which  a  steering  arm  is  attached,  and  a  rotary  movement  of 
the  hand  wheel  will  produce  a  reciprocating  movement  of  the  steer- 
ing arm  at  the  lower  end  of  the  steering  column.  The  steering  arm 
is  coupled  to  one  of  the  steering  knuckles  of  the  front  axle  by  a 
connecting  link  and  the  movement  imparted  to  the  one  steering 
knuckle  is  translated  to  the  other  one  by  means  of  the  tiebar  which 
joins  them. 

The  form  of  steering  gear  outlined  at  B  is  a  simpler  one,  but  it 
does  not  incorporate  the  good  features  of  the  worm-gear  type.  It 
consists  of  a  spur  pinion  at  the  end  of  the  steering  post  which  meshes 
with  the  spur-gear  rack  actuated  when  the  hand  wheel  is  turned  in 


476  The  Modern  Gasoline  Automobile 

such  a  way  that  the  rotary  motion  of  the  wheel  is  transformed  to  a 
reciprocating  movement  of  the  rack.  The  rack  is  directly  attached  to 
one  of  the  steering  knuckles  by  a  drag  link  coupled  to  an  extension 
from  one  of  the  steering  arms.  In  a  modification  of  this  type  a  bevel 
gear  is  used  at  the  lower  end  of  the  steering  post  and  a  bevel-gear 
sector  is  utilized  to  actuate  the  drag  link.  The  principle  of  action  is 


ront  Axle 

o£* 

Steering  Knuckle 


Fig.  279. — How  Front  Wheels  of  Motor  Cars  are  Moved.  A — Conventional 
Worm-Gear  Reduction  Steering  Arrangement.  B — Simple  Rack  and 
Pinion  System  Used  on  Light  Cars. 

the  same  as  in  the  form  described,  however,  and  while  either  of  these 
forms  may  be  applied  to  light  cars  and  make  for  ready  control  be- 
cause they  are  quick  acting  they  are  not  desirable  on  heavy  vehicles 
because  they  do  not  provide  the  feature  of  irreversibility  which  is 
necessary. 

The  factor  of  irreversibility  in  steering  gearing  is  one  that  was 
formerly  a  point  o.f  contention  among  authorities  on  automobile  con- 
struction. It  was  argued  that  the  irreversible  form  does  not  provide 
that  quick  action  which  is  considered  necessary  to  secure  prompt  con- 
trol of  the  car.  At  the  other  hand,  the  strictly  reversible  gear  such  as 
the  spur  rack  and  pinion,  which  is  especially  quick  acting,  will  tire 
the  operator  whenever  the  car  is  operated  on  rough  roads,  as  every 
inequality  of  the  road  service  will  tend  to  produce  a  corresponding 


The  Modern  Gasoline  Automobile 


477 


side  motion  of  the  wheel  which  will  mean  considerable  play  at  the 
rim  of  the  steering  wheel. 

Some  engineers  who  contended  that  the  worm  and  sector  gear 
were  liable  to  wear  devised  combination  forms  in  which  a  screw  and 


Spark  Leuer 


Throttle  Leuer 


Steering  Post 


Bevel  Gears 


Fig.  280. — Unconventional  Steering  Gear  Employing  Threaded  Steering  Post 
and  Movable  Nut  with  Rack  to  Engage  Sector  on  Steering  Arm  Shaft. 

nut  principle  was  combined  with  a  rack  and  sector  gear,  the  object 
being  to  provide  a  largely  increased  bearing  surface  on  the  threads 
and  gear  teeth  and  in  this  manner  reduce  wear. 

A  gear  of  this  type  is  shown  at  Fig.  280.     The  nut  or  internally 


478  The  Modern  Gasoline  Automobile 

threaded  member  is  held  from  turning  by  various  methods,  such  as 
flattening  one  side  and  having  this  in  contact  with  the  walls  of  the 
casing,  by  the  use  of  keys  or  dowel  pins,  or  merely  by  the  pressure 
of  the  rack  and  sector  shown  in  illustrations.  The  advantage  of  this 
form  of  steering  gear  is  that  it  is  wholly  irreversible  and  at  the  same 
time  a  minimum  of  effort  is  needed  on  the  part  of  the  driver  to 
properly  control  a  very  heavy  car.  The  amount  of  movement  of  the 
nut,  up  and  down,  is  regulated  by  the  pitch  and  angle  of  the  thread 
and  as  the  nut  is  provided  with  a  spur  rack  its  rectilinear  motion  is 
transformed  into  an  oscillating  movement  o'f  the  steering  arm  at- 
tached to  the  spur-gear  sector. 

The  worm  and  segment  type  of  steering  gear  is  without  doubt  the 
most  popular  with  automobile  manufacturers  of  this  country  and 
Europe.  It  is  simple,  compact,  and  positive  in  action.  The  steering 
post  carries  a  worm  at  its  lower  end,  as  shown  at  Fig.  281.  This 
in  turn  meshes  with  a  suitable  worm  wheel  or  segment  attached  to 
the  steering  arm.  The  worm  when  turned  will  produce  a  fore  and 
aft  movement  of  the  steering  arm  which  in  turn  is  transmitted  to  the 
wheels  by  suitable  leverage.  This  type  of  gear  must  be  maintained 
in  perfect  adjustment  and  be  well  lubricated  at  all  times.  The  great- 
est defect  is  the  wear  that  will  exist  between  the  worm  and  worm- 
gear  teeth,  and  the  difficulty,  of  devising  any  really  practical  method  of 
taking  up  the  play.  The  constant  oscillations  of  the  vehicle  wheels 
will  cause  the  sector  teeth  and  worm  thread  to  wear  at  one  place, 
which  corresponds  to  the  straightahead  position  of  the  gear. 

.This  may  be  taken  up  in  most  forms  by  the  use  of  eccentric  bush- 
ings in  which  the  sector  shaft  is  mounted,  these  being  moved  in  such 
a  way  that  the  sector  teeth  are  brought  into  closer  engagement  with 
the  thread  of  the  worm.  This  method  is  not  desirable  because  if  the 
eccentric  bushings  are  turned  enough  to  take  up  the  lost  motion 
existing  between  the  teeth,  the  change  in  worm-gear  position  would 
cause  binding  between  those  portions  which  had  not  worn  as  much 
and  which  were  brought  into  play  only  when  it  was  desired  to  turn 
the  wheels  to  nearly  the  extreme  angular  position.  The  preferred 
method  is  that  outlined  at  Fig.  281.  In  this  a  full  worm  wheel  is 
used  instead  of  a  sector  and  when  wear  occurs  at  one  point  the  worm 
wheel  is  removed,  the  hand  wheel  and  worm  are  given  a  complete  turn, 


Tlie  Modern  Gasoline  Automobile 


479 


and  the  worm  wheel  is  replaced  in  such  a  way  that  a  new  set  of  teeth 
on  both  worm  and  worm  gear  will  be  in  mesh. 

With  all  conventional  forms  of  steering  gears  the  object  has  been 
to  get  a  complete  sweep  of  the  front  wheels,  that  is  to  turn  them 
from  one  extreme  position  to  the  other  with  about  one  and  one  half 


'Spark  Lever  Bod 

-Throttle  Control  Tube 
-Sector  Anchorag-e 


Spark  Lever 


Steering:  Post 


Worm 
Case 


Gear 


Spark  Lever  Gear 
Throttle  Lever  Gear 
Steering-  Arm 


Ball  Thrust 


Fig.  281. — Construction  of  Worm  and  Worm-Gear  Reduction  Gearing  for  Steering 

Purposes. 

turns  of  the  hand  wheel.  Anything  slower  than  this  will  be  so  tardy 
of  action  that  it  will  be  difficult  to  steer  the  car  properly  and  quickly 
at  anything  but  low  speed.  On  some  heavy  commercial  vehicles,  how- 
ever, it  is  necessary  to  provide  lower  reduction,  and  two  or  two  and  a 
half  turns  of  the  steering  wheel  are  sometimes  necessary  to  produce 
the  proper  degree  of  movement  of  the  front  wheels.  This  is  not  a 
point  that  can  be  seriously  objected  to  when  one  considers  the  low 
speed  of  the  conventional  motor  truck.  On  high-speed  cars  some 
authorities  claim  that  one  turn  of  the  wheel  to  produce  a  full  move- 
ment of  the  steering  wheel  is  entirely  satisfactory,  as  it  permits  han- 
dling the  car  with  minimum  lag  and  makes  it  quick  to  respond  to  the 
control  gearing  at  all  speeds. 

It  is  common  practice  on  most  motor  cars  to  combine  the  motor- 


480 


The  Modern  Gasoline  Automobile 


controlling  levers  with  the  steering  gear  in  such  a  way  that  the  speed 
of  the  motor  may  be  varied  as  desired  without  the  operator  removing 
his  hands  from  the  steering  wheel.  The  manner  in  which  this  may 


Steering  "Wheel 
Spokes 


Steering  Wheel 
Rim 

Spark  Lever 

Throttle  Lever 


Fixed  Sector 


Steering  Post  Tu 
Attached  to  Worm 


Spark  Time  Lever 
Throttle  Lever 


Spark  Lever 
Control  SfTaft 


Central  Rod  for 
Spark  Control 


Worm 

Worm  Gear  Sector 
Worm  Gear  Case 


Bevel  Gears 


£?cvci  \_rcaio 

Ball  Thrust 
Ball  Joint       DragLink    Bearing 


Fig.  282.— Typical  Steering  Post  Assembly  Showing  Hand  Wheel  and  Motor 
Controlling  Levers.  Sectional  View  of  Worm  and  Worm  Wheel  and 
Steering  Arm  Connecting  Member. 


be  accomplished  is  clearly  shown  in  the  steering-gear  design  depicted 
at  Fig.   2*82.     In  this  the  steering  wheel   is   attached  to   a  tubular 


The  Modern  Gasoline  Automobile  481 

steering  post,  through  the  center  of  which  a  rod  mounted  inside  of 
two  concentric  tubes  is  passed.  The  outer  tube  is  anchored  at  the 
bottom  end  of  the  steering-gear  casing  and  carries  the  sector  on  which 
the  spark  and  throttle  levers  move.  The  short  lever  is  attached  to 
the  rod  passing  through  the  center  of  the  assembly,,  and  this  in  turn 
actuates  by  means  of  bevel  gearing  an  auxiliary  control  shaft  mounted 
in  front  of  the  steering-gear  assembly.  The  long  lever  is  attached  to 
the  tube  which  surrounds  the  central  rod,  and  this  member  also  carries 
a  gear  at  its  lower  end  which  engages  a  tube  surrounding  the  spark- 
lever  control  shaft  at  the  front  of  the  steering  gear.  The  spark 
timer  or  commutator  is  attached  to  the  upper  lever  while  the  car- 
buretor throttle  is  operated  from  the  lever  immediately  below  that 
controlling  the  spark-timing  device. 

As  the  sector  is  anchored  at  the  lower  end  of  the  gear  case  it 
remains  stationary  when  the  steering  wheel  is  turned  and  the  motor- 
control  levers  always  maintain  a  fixed  relation  to  each  other  and  the 
operator.  All  gearing  is  enclosed  and  thoroughly  lubricated,  and  as 
there  is  but  little  chance  for  dirt  to  get  in,  the  mechanism  is 
very  enduring.  Ball-thrust  bearings  are  provided  above  and  below 
the  worm  to  take  the  end  thrust  which  results  when  it  is  turned. 
This  makes  the  gearing  much  easier  to  operate  than  would  be  the  case 
if  the  considerable  amount  of  end  thrust  present  was  taken  on  plain 
bearings. 

Front  Axle  Forms. — Various  front  axle  constructions  used  in  auto- 
mobiles follow  a  common  design  and  the  same  general  principle  of 
action  prevails  in  all.  Front  axles  differ  from  each  other  only  in 
matters  of  minor  constructional  detail,  such  as  the  type  of  steering 
knuckles  used  and  whether  the  axle  is  a  one-piece  forging  or  a  built- 
up  structure.  Axles  of  good  design  are  shown  at  Fig.  283.  That  at 
A  is  composed  of  a  one-piece  I-section  drop  forging  of  steel  which 
has  the  advantage  of  having  the  steering-knuckle  yokes  and  the 
spring  pads  formed  integral.  This  is  the  type  most  generally  used 
because  it  is  exceptionally  strong  and  when  properly  designed  is  not 
unnecessarily  heavy. 

One  of  the  front  hubs  is  shown  in  section  in  the  plan  view  of  the 
axle  depicted  at  A.  The  hub  is  mounted  on  ball  bearings,  which  in 
turn  are  supported  by  the  spindle  which  forms  part  of  the  steering 


482 


The  Modern  Gasoline  Automobile 


knuckle.  A  long  through  bolt  passes  through  the  steering  knuckle 
and  acts  as  a  bearing  for  it  to  swivel  on.  Steering  arms  project 
from  each  knuckle  and  are  joined  together  by  a  tiebar. 

The  construction  of  the  axle  depicted  at  B  is  practically  the  same 
in  general  design  as  that  shown  above  it.     It  differs  in  the  important 


Spring:  Pad 


Dragr  Link  Ar 


TOP  VIEW 


Steering1  Arm 


Steering-  Knuckle 
>1  Forging- 


SIDE  VIEW 


teering  Knuckle 


Wheel  Hub  \\  Steering-  Arm  SPrin^  Seat 


Steel  Tube 
Tie  Bar 


Steering- 
Spindle 


Fie.  283. — Typical  Front  Axle  Types.     A — Forging  of  I  Section.     B — Tubular 

Axle. 

respect  that  the  axle  proper  is  formed  of  a  piece  of .  steel  tubing  to 
which  the  separately  forged  yokes  and  spring  seats  are  secured  by 
brazing.  Those  .who  favor  the  tubular  axle  claim  greater  flexibility 
and  lightness  combined  with  adequate  strength,  while  the  adherents 
of  the  I-beam  construction  advance  the  argument  of  exceptional 
strength  and  contend  that  flexibility  is  not  a  point  of  moment  com- 
pared to  rigidity  of  the  structure.  As  a  general  rule,  tubular  axles 


The  Modern  Gasoline  Automobile 


483 


are  employed  on  light  cars,  while  the  heavier  forged  form  is  utilized 
extensively  on  the  larger  vehicles.  Various  forms  of  steering 
knuckles  and  bearings  used  for  mounting  the  front  wheel  are  shown 
at  Fig.  284.  At  A  an  Elliot  type  knuckle,  which  is  provided  with 
a  roller-thrust  bearing  at  its  upper  end  to  take  the  thrust  due  to  the 
weight  of  the  car,  is  shown.  The  wheel  hub  is  mounted  on  taper- 
roller  bearings  secured  to  the  spindle  in  the  usual  manner.  Another 


Spindle  Pin 

Roller  \ 

Bearing- 


Ta 


Steering  Knuckle 
Bolt 
Wheel  Hub 


Steering 
Spindle 


Fig.  284.— Typical  Front  Hub  and  Steering  Knuckle  Designs.  A — Elliot  Type 
Hub  with  Taper  Roller  Bearings.  B — Front  Hub  Mounted  on  New  Depar- 
ture "Radax"  Ball  Bearings.  C — Mercedes  Type  Steering  Knuckle, 
Hub  Mounted  on  Single  and  Double  Row  Bearings. 

Elliot  knuckle  is  depicted  at  B,  but  in  this  construction  the  front  hub 
is  supported  on  ball  bearings  of  the  cup  and  cone  type.  The  steering 
knuckle  depicted  at  C  is  a  modification  of  the  Mercedes  design,  and 
in  this  the  yoke  forms  part  of  the  wheel  spindle  and  oscillates  on  a 
pin  carried  by  the  end  of  the  forged  steel  axle.  Special  attention 
is  directed  to  the  form  of  ball  bearings  utilized  for  supporting  this 
hub.  Practically  all  of  the  weight  is  taken  by  a  large  New  Depart- 
ure double  purpose  bearing  specially  adapted  to  support  both  end 
thrust  and  radial  loads.  This  forms  a  very  effective  bearing  and  is 
often  used  at  points  in  the  motor-car  chassis  where  severe  loads  are 
to  be  resisted.  The  general  construction  of  these  steering  knuckles 
and  the  mode  of  application  of  the  bearings  on  wtiich  the  hubs  re- 
volve are  so  clearly  shown  that  further  description  is  not  necessary. 

Typical  Power  Transmission  Systems. — One  of  the  factors  making 
for  motor-car  efficiency  is  the  system  of  transmission  employed  by 
which  the  power  delivered  by  the  engine  is  transmitted  to  the  rear 


484  The  Modern  Gasoline  Automobile 

wheels,  and  the  most  efficient  system  is  obviously  that  which  will 
deliver  the  power  to  the  rear  wheels  with  minimum  loss.  The  com- 
mon methods  of  power  transmission  are  outlined  at  Fig.  285.  That 
at  A  is  the  system  formerly  used  on  many  light  cars  which  derived 
their  power  from  a  single-cylinder  engine  placed  lengthwise  in  the 
chassis.  The  drive  from  the  sprocket  on  the  planetary  gearset  is  by 
means  of  a  chain  to  a.  sprocket  on  the  differential  gear  of  the  rear 
axle.  This  was  one  of  the  most  direct  methods  of  transmission 
possible  and  was  remarkably  efficient  as  long  as  the  chain  was  kept 
clean,  properly  oiled,  and  in  correct  adjustment.  The  efficiency  of 
this  arrangement  was  very  high,  and  about  ninety  per  cent  of  the  en- 
gine power  was  delivered  to  the  wheels  on  the  direct  drive  and  about 
seventy-five  per  cent  when  the  planetary  gearset  was  in  operation. 

The  system  shown  at  B  was  formerly  very  popular  on  all  classes 
of  touring  cars,  but  is  seldom  used  at  the  present  time  except  in 
heavy  commercial  vehicles.  With  this  system  the  differential  gear 
is  carried  adjacent  to  the  gearset  and  driving  shafts  extend  therefrom 
to  sprockets  at  each  side  of  the  frame.  The  drive  from  the  counter- 
shaft member  is  by  means  of  driving  chains  to  sprockets  on  each  rear 
wheel.  The  wheels  are  mounted  so  they  revolve  on  a  stationary  axle. 
It  is  believed  that  this  construction  is  stronger  than  the  live  axle 
for  heavy  vehicles,  and  it, is  also  used  because  it  permits  the  designer 
to  obtain  a  double  reduction  and  very  low  ratios  of  speed,  which 
make  it  very  suitable  for  motor-truck  service.  The  efficiency  of  this 
method  of  driving  is  lower  than  that  in  which  either  chains  or  gears 
are  used  alone,  and  even  when  the  gearset  is  in  the  direct  drive 
position  or  high-speed  ratio  there  is  a  loss  of  twenty-five  per  cent  in 
transmission,  which  gives  a  net  efficiency  of  seventy-five  per  cent  under 
most  favorable  conditions.  When  on  the  lower  ratios,  which  demand 
the  use  of  the  change-speed  gearing,  the  efficiency  is  reduced  to  about 
sixty  per  cent. 

Various  forms  of  shaft-drive  systems  are  popular  at  the  present 
time  and  the  two  methods  of  employing  shafts  differ  merely  in  detail. 
In  the  diagram  shown  at  Fig.  285,  C,  two  universal  joints  are  em- 
ployed and  a  length  of  driving  shaft.  One  of  these  joints  is  mounted 
at  the  end  of  the  gear  box  on  the  power  plant  unit,  while  the  other 
flexible  member  is  attached  to  the  differential  housing.  The  drive 


Clutch  Driving  Chain 


Fig.  285.— Methods  of  Power  Transmission  Employed  by  Motor  Car  Designers. 
A— Single    Chain    Drive    from    Planetary    Gearset    to    Live    Rear    Axle. 

LB— Side  Chain  System.     C— Drive  by  Exposed   Shaft   Having   Two  Uni- 
versal Joints.    D— Drive  Shaft  Enclosed  in  Torque  Tube  Needs  but  One 
Universal  Joint. 
485 


486 


The  Modern  Gasoline  Automobile 


from  the  shaft  to  the  wheels  may  be  by  bevel  or  worm  gearing  and 
when  this  system  is  employed  it  is  necessary  to  use  some  form  of 
radius  rod  member  to  keep  the  axle  in  proper  relation  with  the  frame. 
When  the  method  depicted  at  D  is  employed  but  one  universal 
joint  is  needed.  The  driving  shaft  is  encased  in  a  tubular  member 
usually  attached  to  the  frame  in  such  a  manner  that  it  serves  as  a 
radius  member  and  permits  the  axle  to  move  up  and  down  under  the 
influence  of  rough  road  surfaces,  but  does  not  permit  end  movement 
of  the  axle.  The  efficiency  of  the  shaft-driving  systems  is  very  high 
compared  to  the  double-chain  drive  and  as  all  parts  are  always  en- 


Propeller  Shaft 
Straight  Line  Transmission 

Drive  piy  wheel 


Fig.  286. — Chassis  of  Knox  Car,  in  which  Straight-Line  Driving  Shaft  is  Utilized, 
which  Permits  Power  Transmission  with  but  Minimum  Loss. 

closed  and  run  in  lubricant  the  efficiency  may  be  conserved.  While 
the  power  loss  with  a  bevel-gear  and  shaft-driving  system  is  apt  to  be 
a  little  higher  than  the  single-chain  method  when  both  are  new, 
deterioration  is  apt  to  be  more  rapid  in  the  chain-driven  cars.  If 
care  is  taken  to  install  the  power  plant  so  the  propeller  shaft  will  be 
on  a  straight  line  with  the  engine  crank  shaft,  as  depicted  at  Fig.  286, 
but  fifteen  per  cent  of  the  power  will  be  lost  in  transmission.  If  the 
driving-shaft  angle  increases  the  efficiency  will  be  lower.  A  safe  rule 
for  estimating  this  is  given  by  some  authorities  as  one  per  cent  loss 
for  each  degree  of  shaft  inclination. 

Rear  Axle  Forms. — In  any  motor  car  the  rear  axle, is  an  impor- 
tant member  as  it  combines  two  functions,  one  being  that  it  is  de- 


The  Modern  Gasoline  Automobile  487 

pended  upon  to  support  part  of  the  car  weight  and  that  it  must  also 
drive  the  vehicle.  The  rear  axle  forms  in  common  use  are  known 
as  the  "  live  "  or  "  dead  "  types.  The  latter  is  the  simplest  and  is 
built  on  the  same  principle  as  that  generally  utilized  in  horse-drawn 
vehicles.  This  construction  serves  merely  to  support  the  weight 
of  the  car  and  the  power  of  the  engine  is  delivered  to  the  wheels 
by  means  previously  described. 

Two  types  of  live  axles  are  shown  at  Fig.  287.  That  at  A  is 
the  simplest  form  and  in  this  the  wheel  hubs  are  mounted  directly 
on  the  axle  shaft,  and  these  members  are  depended  upon  to  carry  the 
weight  of  the  car  as  well  as  to  transmit  to  the  wheels  the  power  de- 
livered to  the  bevel  gearing  and  the  propeller  shaft.  In  this  construc- 
tion the  axles  revolve  in  roller  bearings  carried  by  the  axle  housing. 
The  form  shown  at  B  is  known  as  the  "  floating  type  "  because  the 
wheel  hubs  are  mounted  directly  on  the  substantial  housing  member 
which  is  called  upon  to  support  the  weight  of  the  car.  The  wheels 
can  revolve  freely  on  the  housing  because  they  are  mounted  on  ball 
bearings.  The  axles  float  in  the  housing  and  are  called  upon  only  to 
transmit  power  to  the  hubs  and  are  not  depended  upon  to  sustain 
any  of  the  car  weight. 

The  live  axle  depicted  at  A  has  been  adapted  to  a  certain  extent 
on  light  cars,  but  the  full  floating  type  depicted  at  B  is  much  more 
efficient  and  is  used  on  heavy  vehicles.  It  will  be  evident  that  should 
the  simple  form  of  live  axle  deflect  under  load  the  shafts  will  bind 
and  considerable  loss  of  power  will  obtain.  In  the  construction  out- 
lined at  B  the  substantial  housing  members  have  ample  capacity  to 
sustain  the  load,  and  as  the  driving  shaft  does  not  become  cramped 
through  deflection  it  will  deliver  the  power  to  the  wheels  much  more 
efficiently.  A  strong  advantage  of  the  floating  type  rear  axle  is  that 
the  driving  shafts  and  differential  gearing  may  be  removed  without 
relieving  the  housing  of  the  car  weight.  If  it  is  desired  to  take  the 
simple  live  axle  shown  at  A  apart  it  will  be  necessary  to  remove  it 
from  the  car. 

The  fixed  or  stationary  axle  construction  is  clearly  shown  at  Fig. 
287,  C.  In  this  the  wheel  hubs  are  mounted  on  ball  bearings  which 
permit  them  to  revolve  about  the  fixed  axle  spindle.  The  hubs  are 
turned  by  chain  connection  with  suitable  driving  sprockets  on  a  coun- 


488 


The  Modern  Gasoline  Automobile 


tershaft.  The  advantage  of  the  fixed  or  stationary  axle  construction 
is  that  it  is  a  much  simpler  assembly  than  the  live  axle  forms,  and 
as  it  may  be  constructed  of  few  pieces  it  is  apt  to  be  considerably 


Ball  Thrust 

Roller  Bearings 
Driving  Gears 


B       JJIL     /BallBeannS  Brake  Drum 

Axle  Housing  m^-feL          ^-Driving  Gears 


Stationary  "Wheel  Spindle 


Fig.  287.— Rear  Axle  Types  Generally  Used.  A— Live  Rear  Axle  Using  Shafts 
which  Transmit  Power  and  also  Carry  Weight  Equipped  with  Roller  Bear- 
ings. B— Full  Floating  Type  Bevel-Gear  Drive  Axle.  C— Stationary  Axle 
with  Chain  Drive  to  Free  Wheels. 


stronger  than  the  built  up  live  axles.     It  is  contended  that  the  lighter 
axle,  which  is  practically  free  from  any  delicate  mechanism,,  is  more 


The  Modern  Gasoline  Automobile 


489 


desirable  because  there  is  less  weight  carried  directly  on  the  tires. 
In  the  live  axle  forms  some  method  of  driving  must  be  provided  and 
some  form  of  differential  gearing  must  be  included  in  the  rear  hous- 
ing. It  is  contended  that  while  this  construction  is  very  suitable  for 
light  cars  such  as  roadsters,,  or  touring  vehicles,  that  it  would  be 
extremely  heavy  if  it  was  built  of  adequate  strength  to  resist  the 
stresses  incidental  to  motor-truck  operation. 

In  the  fixed  or  stationary  axle  with  the  wheels  independent  of 
each  other,,  a  differential  gear  must  be  provided  just  as  much  as  in 
the  live  axle  forms.  This  member  is  usually  driven  by  gearing  and 
must  be  installed  on  some  form  of  a  countershaft  arrangement  which 


evel  Gear  Housing 
of  Driving:  Axle 


Stationary  Load  Carrying  Axle 


Fig.  288.— Combined  Live  and  Stationary  Axle  which  Combines  Good  Features 
of  Both  Types  and  Eliminates  All  Objections  to  Either.  The  Strongest 
Possible  Construction. 

is  attached  to  the  frame.  It  is  contended  that  mechanism  supported 
by  the  frame  which  is  mounted  on  resilient  springs  will  not  be  so 
apt  to  get  out  of  order  as  that  which  is  attached  directly  to  the  axle, 
and  which  is  kept  from  direct  stress  of  the  road  shock  only  by 
means  of  the  more  or  less  resilient  tires  with  which  the  wheels  are 
provided. 

Axles  have  been  evolved  in  which  engineers  sought  to  combine 


490  The  Modern  Gasoline  Automobile 

the  strength  of  the  dead  axle  with  the  efficiency  of  the  live  axle.  One 
of  these  combinations  is  shown  at  Fig.  288.  It  consists  of  a  sta- 
tionary load-carrying  axle  forging  on  which  the  wheels  revolve,  this 
serving  to  take  the  direct  load  of  the  car  as  well  as  serving  as  a 
support,  for  the  bevel  gear  and  differential  housing  that  receives  the 
power  of  the  engine  and  directs  it  to  the  wheels  by  means  of  suitable 
shafts  extending  thereto  from  each  side  of  the  gear  box.  These  com- 
posite forms  are  necessarily  considerably  heavier  than  either  the  live 
axle  or  the  fixed  axle  forms  as  they  are  a  combination  of  both,  and 
as  they  are  more  expensive  in  first  cost  and  add  a  large  item  to  the 
unsprung  weight  of  the  car  they  are  used  very  seldom  at  the  present 
time. 

Purpose  of  Differential  Gear. — One  of  the  most  important  elements 
of  any  form  of  automobile-driving  system  is  the  differential  gear,  but 
as  this  is  usually  placed  at  a  point  where  it  is  not  easily  seen  by  the 
motorist  and  as  but  very  little  trouble  is  experienced  from  this 
mechanism,  many  owners  of  cars  are  not  aware  of  its  existence  and 
do  not  realize  the  important  work  performed  by  this  relatively  simple 
component.  Without  a  differential  gear  it  would  be  difficult  to  con- 
trol the  machine  when  driving  around  corners,  so  this  really  performs 
an  important  function  with  both  steering  and  driving  systems. 

When  turning  corners  with  a  four-wheel  vehicle  the  outer  wheels 
must  turn  at  a  higher  rate  of  speed  than  the  inner  ones  because  they 
are  describing  a  larger  arc  of  the  circle.  The  more  sharply  the 
vehicle  is  turned  the  greater  the  difference  in  velocity  between  the 
inner  and  outer  wheels.  In  a  horse-drawn  conveyance  all  the  wheels 
are  independent  of  each  other  and  may  all  revolve  at  different  speeds 
if  necessary,  without  interfering  with  each  other  or  impairing  the  ac- 
tion of  the  conveyance.  In  an  automobile  different  conditions  prevail 
because  while  the  front  wheels  are  usually  independent  of  each  other, 
the  driving  wheels  must  be  connected  together  so  that  each  will  receive 
its  share  of  the  energy  produced  by  the  motor  and  will  perform  its 
quota  of  the  work  incidental  to  propelling  the  vehicle. 

In  order  to  permit  one  of  the  driving  wheels  to  turn  at  a  lower 
speed  than  its  mate  in  rounding  a  corner  the  balance  or  differential 
gear  is  used.  Its  simplest  application  is  shown  at  Fig.  289.  From 
this  it  is  patent  that  the  driving  axle  is  split  in  the  center  and  that 


The  Modern  Gasoline  Automobile 


491 


the  wheels  are  mounted  on  and  driven  by  distinct  shafts.  At  the 
inner  end  of  each  shaft  a  bevel  gear  is  carried,  these  being  firmly  se- 
cured to  the  axles  so  they  revolve  with  them.  The  main  bevel-driven 
gear,  which  is  actuated  by  the  driving  pinion  turned  by  the  engine 


Differential 
Pinions 


Driving  Pinion 


Axle  Shaft  No.  1 


Gear  No.  1 


Differential 
Pinion 


Driven  Gear 


Fig.  289. — Illustrating  Differential  Gear  Action  when  Applied  to  Bevel-Gear 

Drive  Axle. 

shaft,  is  mounted  independent  of  the  axles  and  is  .coupled  to  them 
by  means  of  small  bevel  pinions  which  are  applied  so  that  they  will 
drive  the  gears  on  the  axle  shafts.  Assuming  that  all  the  gears  are  in 
mesh,  as  outlined,  and  that  power  is  being  applied  to  the  driven  gear, 
and  that  the  resistance  to  traction  is  the  same  at  both  rear  wheels, 
the  entire  assembly  comprised  of  driven  gear,  the  differential  pinions 
attached  to  it  and  the  axle  shafts  revolve  as  a  unit. 

If  the  resistance  against  the  driving  wheels  varies  so  one  wheel 
tends  to  revolve  faster  than  the  other,  the  differential  pinions  will 
not  only  turn  around  on  the  studs  on  which  they  are  mounted,  but  at 
the  same  time  will  run  around  the  gears  on  the  axle  shafts,  because 
the  bevel-driven  gear  is  carrying  the  studs  on  which  the  differential 
pinions  revolve  forward.  When  turning  a  corner  the  outer  wheel 
must  turn  so  much  faster  than  the  inner  member  that  it  is  just  the 
same  as  though  one  of  the  wheels  was  held  stationary  and  the  other 


492  The  Modern  Gasoline  Automobile 

turned.  If  both  wheels  are  turning  forward  at  the  same  speed,  the 
differential  pinions  remain  stationary  and  act  simply  as  a  lock 
which  fomis  a  driving  connection  between  gear  No.  1  on  axle  shaft- 
No.  1  and  gear  No.  2  on  axle  shaft  No.  2.  This  will  mean  that  both 
wheels  must  turn  in  the  same  direction  as  long  as  the  work  is  uni- 
formly distributed.  Just  as  soon  as  the  resistances  are  unequal  the 
differential  pinions  will  turn  on  their  supporting  stud,  and  one  mem- 
ber may  turn  at  comparatively  slow  speed  while  the  other  revolves  at 
a  much  faster  rate. 

The  action  of  the  differential  pinions  may  be  clearly  understood 
by  reference  to  Fig.  289  and  giving  due  consideration  to  the  follow- 
ing principles:  The  same  resistance  at  the  point  of  contact  between 
the  driving  wheels  and  the  ground  prevents  the  pinions  from  revolv- 
ing on  their  own  studs,  and  in  this  case  they  are  carried  around  by 
the  supporting  members  and  the  ring  gear.  If  the  resistance  upon 
axle  shaft  No.  1  is  greater  than  that  on  axle  shaft  No.  2,  the  ring 
gear  will  rotate  forward  with  the  wheel  offering  the  least  resistance 
and  the  differential  pinions  will  turn  on  their  studs  and  run  over  the 
surface  of  the  gear  which  tends  to  remain  stationary,  this  being  the 
one  against  which  there  is  the  greatest  resistance.  The  differential 
pinions  can  thus  turn  independently  of  one  gear  wheel  and  run  over 
its  surface  without  turning  it,  and  at  the  same  time  act  as  a  clutch- 
ing member  of  sufficient  capacity  on  the  other  gear  and  axle  to  carry 
them  in  the  same  direction  as  the  ring  gear  and  at  a  ratio  of  speed 
which  will  depend  upon  the  difference  in  resistance  between  the  driv- 
ing members  and  the  ground. 

While  the  differential  gear  described  is  of  the  bevel  pinion  type, 
other  forms  have  been  devised  in  which  the  differential  action  is 
obtained  by  means  of  spur  gearing  which  utilizes  the  same  principle 
of  compensation.  Various  friction  and  leverage  combinations  have 
been  adapted  in  an  endeavor  to  secure  a  differential  action,  but  these 
have  eventually  been  displaced  by  the  simpler  and  more  efficient 
geared  forms.  The  differential  gear  which  utilizes  bevel  pinions  is 
the  form  that  is  more  generally  used,  and  has  proved  to  be  the  most 
efficient  and  enduring.  The  differential  gear  is  usually  incorporated 
in  the  rear  axle  if  the  drive  is  by  shaft  or  single  chain,  and  in  the 
countershaft  if  transmission  is  by  means  of  side  chains.  The  con- 


The  Modern  Gasoline  Automobile 


493 


struction  of  typical  differential  gears  and  bevel-driving  gear  assembly 
is  clearly  shown  at  Figs.  290  and  291 ;  the  former  is  utilized  on  light 
vehicles  and  is  mounted  on  flexible  roller  bearings,  while  the  other 


Bevel  Gear 


Eoller  Bearing 


Housing- 


Differential  Gears 


Fig.  290.— Bevel-Gear  Drive  Assembly  of  Ford  Light  Cars  Mounted  on  Hyatt 
Flexible  Roller  Bearings. 

construction  is  a  type  more  suitable  for  heavier  cars  and  is  mounted 
on  tapered  roller  bearings. 

Worm-Gear  Driving. — A  number  of  designers  have  used  worm 
gearing  in  connection  with  shaft-driving  systems  instead  of  the  bevel 
gears  so  generally  adapted.  The  greatest  development  of  worm  driv- 
ing has  taken  place  abroad,  and  very  efficient  and  enduring  mech- 
anisms have  been  evolved.  The  advantages  of  the  worm  gear  are 
more  apparent  in  motor-truck  construction  than  in  pleasure-car  prac- 
tice, though  it  has  been  used  to  advantage  in  both  classes  of  vehicles. 
A  high  degree  of  efficiency  has  been  obtained  by  using  worms  of 
peculiar  tooth  formation  which  have  a  spiral  angle  often  approaching 
45  degrees.  Such  worms  may  have  from  six  to  ten  or  twelve  threads, 


494 


The  Modern  Gasoline  Automobile 


and  they  are  perfectly  reversible,  when  contrasted  to  the  single- 
threaded  worm  used  in  steering  gears,  which  are  an  irreversible  form. 
Obviously  the  worm  employed  for  driving  an  automobile  must  be 
perfectly  reversible  to  be  practical,  as  very  often  conditions  will  be 


Bevel  Driving  Gear 


Axle  S 


Pinion  Drive  Shaft 

Bevel  Driving  Pinion 
Axle  Shaft 

Axle  Housing 


Differential  Gearing 


Taper  Roller  Bearing 
Housing  Cover 


Fig.  291.— Bevel-Gear  Drive  Assembly  Mounted  on  Timken  Tapered  Roller 

Bearings. 

such  that  the  rear  wheels  and  worm  gear  to  which  they  are  attached 
must  turn  the  worm  and  driving  shaft,  as  in  descending  hills,  with 
the  rear  axle  overrunning  the  engine. 

This  form  of  gearing  offers  many  inducements  and  has  positive 
advantages  which  commend  it  as  a  means  of  direct  final  drive.  Any 
range  of  reduction  that  would  be  likely  to  be  needed  may  be  obtained 
with  but  a  single  pair  of  worm  gears,  and  reductions  of  twenty  to  one 
may  be  as  easily  accomplished  as  securing  the  higher  ratios  without 
the  efficiency  of  the  combination  being  affected.  It  would  not  be 
possible  to  obtain  as  low  speed  reduction  as  possible  with  worm  gear- 
ing by  the  use  of  a  single  set  of  bevel  gears  or  a  single  pair  of  sprockets 


The  Modern  Gasoline  Automobile 


495 


and  chain  connections,  because  the  driven  member  would  have  to  be 
of  such  large  size  that  it  would  be  difficult  to  place  it  within  the 
confines  of  an  ordinary  axle.  It  is  for  this  reason  that  most  motor- 
truck manufacturers  use  a  combined  bevel  gear  and  chain  drive  and 
a  double  reduction  of  speed  between  the  engine  and  the  rear  wheel. 

Among  some  of  the  advantages  advanced  in  favor  of  worm  gear- 
ing may  be  cited:  It  is  silent  in  operation;  when  properly  designed 
it  will  transmit  eighty-five  to  ninety  per  cent  cf  the  engine  power  to 
the  rear  wheels  on  direct  drive,  and  it  is  extremely  enduring.  Its 
efficiency  under  ideal  conditions  is  equal  to  the  most  accurately  ma- 
chined and  finely  adjusted  bevel  gearing,  and  instead  of  the  efficiency 
becoming  less  as  the  gearing  wears,  it  actually  becomes  more  silent 
and  freer  running  with  use. 

Many  of  the  more  progressive  manufacturers  of  automobiles  are 
giving  the  worm  and  worm-gear  drive  that  consideration  which  means 
its  eventual  adoption.  It  has  been  used  with  success  in  pleasure-car 
applications,  but  its  greatest  field  of  usefulness  will  undoubtedly  be 


Drive  Shaft. 


Thrust  Bearings. 


-Worm. 


Torque 
Member, 


Fig.  292.— Worm-Gear  Driving  Assembly  Utilized  on  Pierce  Motor  Trucks  and 
Form  of  Worm  and  Worm  Wheel  Utilized  in  Power  Transmission. 

the  commercial  vehicle  industry  because  of  its  undoubted  superiority 
over  all  other  forms  of  gearing  from  which  considerable  reductions 
in  ratio  are  demanded  and  where  the  efficiency  of  the  transmission 
system  should  be  conserved  as  much  as  possible.  A  typical  worm- 
gear  assembly  and  the  method  of  mounting  the  worm  in  connection 
with  the  shaft  drive  is  shown  at  Fig.  292,  while  the  illustration  at 


496 


The  Modern  Gasoline  Automobile 


Fig.  293  shows  clearly  the  application  of  worm  and  worm-wheel  drive 


in  a  live  or  floating  axle  construction. 


Worm. 


^Worm  Casing. 


Worm 

Ball  Thrust  Bearing. 
Radial  Load  Bearing 
Spring  Pad. 

£_  SS\    /        ^ 


Truss  Rod. 


Felloe  — 


Fig.  293. — Worm-Gear  Driving  Axle  Used  on  Dennis  (English)  Motor  Cars. 

Axles  Employing  Double  Reduction  Gearing. — The  simplest  form 
of  axle  in  which  two  gear  reductions  are  necessary  is  the  stationary 
or  dead  axle,  but  it  must  be  used  with  the  jack-shaft  combination 
previously  described.  There  is  one  gear  reduction  by  means  of  bevel 
driving  gearing  in  the  countershaft  assembly,  and  the  ratio  between 
the  driving  sprockets  and  the  driven  members  attached  to  the  .wheel 
may  be  altered  so  a  wide  range  of  speed  may  be  obtained.  The  use 
of  a  separate  countershaft  assembly  is  favored  by  the  majority  of 
builders  of  motor  cars  who  find  it  necessary  to  use  two  speed  reduc- 
tions in  ,the  driving  gearing,  and  one  of  the  objections  which  has 
been  advanced  against  the  use  of  exposed  driving  chains  has  been 


The  Modern  Gasoline  Automobile 


497 


overcome  in  many  designs  by  the  use  of  oil -tight  chain  cases  that 
protect  both  chains  and  sprockets  from  grit  and  dirt  and  insure  effi- 
cient operation  because  the  chains  operate  in  an  oil  bath. 

If  a  driving  chain  is  kept  properly  adjusted  and  remains  clean 
and  well  oiled  its  efficiency  will  be  very  high,  and  chain  cases  are 
very  desirable  attachments  to  attain  these  ends.  The  usual  form  of 
chain  case  is  depicted  at  Fig.  294.  In  this  construction  the  case 
proper  is  composed  of  an  aluminum  casting  which  is  also  utilized  as 
a  distance  member  to  maintain  a  fixed  relation  between  the  front 
sprocket  and  that  on  the  driving  wheel.  When  the  cover  is  in  place 


Driving  Chain 


Chain  Case 


Front  Sprocket 


Wheel  Sprocket 


Fig.  294.— Method  of  Enclosing  Driving  Chain  in  Oil-Tight  Casing  to  Secure 
Efficient  Driving  and  Long  Life  of  Mechanism. 

the  assembly  is  oil-tight  and  the  chain  and  sprockets  always  receive 
adequate  lubrication,  which  tends  to  greater  endurance  and  main- 
tenance of  efficiency. 

Some  engineers  do  not  favor  the  chain-driving  method,  and  when 
a  double  speed  reduction  is  necessary  between  the  motor  and  the 
driving  wheels  it  is  incorporated  directly  in  the  rear-axle  structure. 
A  combination  axle  of  this  type,  known  as  the  "  Torbensen,"  is  de- 
picted at  Fig.  295.  This  is  in  reality  a  combination  of  the  live  and 
dead  axle  forms  and  has  been  designed  specifically  for  application  in 
motor-truck  work.  The  differential  gear  is  carried  in  the  casing 
attached  to  the  back  of  the  fixed  axle  and  receives  power  from  the 
engine  through  the  drive  shaft  and  a  pair  of  bevel  gears.  The  wheels 
are  mounted  directly  on  the  ends  of  the  fixed  axle  and  are  driven  from 


498 


The  Modern  Gasoline  Automobile 


the   differential   gear   by   means   of   axles   extending   therefrom   and 
carrying  driving  pinions  of  the  spur  type  which  mesh  with  internal 


Spok 


-e  VBrake  Band 


Wheel  Hub 


Fig.  295. — Sectional  View  of  Torbensen  Axle  for  Motor  Trucks  which  Combines 
Features  of  Both  "Live"  and  "Dead"  Rear  Axle  Forms  and  which  Utilizes 
Two  Driving  Gearing  Sets. 

gears  attached  to  the  wheels.     It  will  be  evident  that  one  reduction 
of  speed  is  obtained  at  the  bevel  gearing,  and  this  would  be  further 


Drive  Shaft. 


I       I  I     ?=|g-lfll  Floating  Axle. 


Fig.  296.— Live  Rear  Axle  with  Combined  Bevel-and  Spur-Gear  Final  Drive. 


The  Modern  Gasoline  Automobile  499 

reduced  by  the  difference  in  ratios  between  the  spur-driving  pinions 
and  the  internal  gears  carried  by  the  wheels. 

The  live-axle  form  shown  at  Fig.  296  is  that  used  on  some  of  the 
Peugeot  (French)  cars  and  also  uses  bevel  and  spur  reduction  gears. 
In  this  case,  however,  but  one  spur  gear  is  used  to  drive  'both  wheels, 
this  being  attached  directly  to  the  differential  gear  case,  and  the 
wheels  are  turned  by  live  floating  axles.  The  first  speed  reduction  is 
by  means  of  the  bevel  gears,  one  of  which  is  driven  by  the  motor,  the 
other  being  attached  to  the  countershaft,  which  also  carries  the  small 
spur-driving  pinion,  which  meshes  with  the  large  gear  on  the  dif- 
ferential case.  The  efficiency  of  either  of  these  axles  will  be  about 
the  same  as  that-  of  the  combination  countershaft  and  side-chain 
drives,  but  those  who  favor  the  latter  construction  advance  the  argu- 
ment that  combining  a  double  reduction  on  the  axle  makes  for  greater 
unsprung  weight  than  is  desirable,  whereas  carrying  the  countershaft 
on  the  frame  makes  it  possible  to  support  it  on  springs,  just  as  the 
greater  part  of  the  power-generating  and  transmission  mechanism  is. 

Utility  of  Motor-Car  Brakes. — One  of  the  most  important  of  the 
components  of  the  motor-car  controlling  system  is  usually  carried 
with  and  forms  part  of  the  rear  construction,  this  being  the  braking 
means  which  is  utilized  to  bring  the  vehicle  to  a  stop  when  it  is  de- 
sired to  arrest  forward  or  backward  motion.  It  will  be  evident  that 
in  a  horse-drawn  vehicle  the  animal  drawing  it  can  be  used  as  a 
brake,  but  that  in  any  form  of  self-propelling  conveyance  it  is  essen- 
tial that  some  means  of  stopping  be  included  in  the  construction. 
Even  if  the  clutch  was  operated  in  such  a  way  that  the  motor  was 
disconnected  from  the  driving  wheels  the  conveyance  would  continue 
to  move  because  it  had  acquired  a  certain  momentum  which  would 
increase  in  value  with  the  weight  of  the  car  and  the  speed  at  which 
it  was  driven. 

On  some  forms  of  horse-drawn  vehicles,  particularly  those  of 
large  capacity,  some  form  of  supplemental  retarding  member  must 
be  provided  to  assist  the  braking  effect  of  the  animal,  which  may  not 
be  sufficient  to  stop  the  vehicle  when  descending  grades  or  when 
operated  with  some  degree  of  speed  on  the  level. 

A  simple  form  of  shoe  brake,  such  as  used  on  a  horse-drawn-con- 
veyance, is  shown  at  Fig.  297,  This  consists  of  a  brake  block  of 


500 


The  Modern  Gasoline  Automobile 


wood  or  other  material  carried  at  the  end  of  a  fulcrumed  lever,  which 
in  turn  is  joined  to  a  pedal  by  a  connecting  link.  When  it  is  desired 
to  bring  the  vehicle  to  a  stop,  a  moderate  degree  of  pressure  at  the 


Brake  Block 
Steel  Tire. 


Fig.  297. — Simple  Form  of  Shoe  Brake  Used  on  Horse-Drawn  Vehicles. 

foot  pedal  will  bring  the  brake  block  in  contact  with  the  periphery 
of  the  wheel,  and  but  a  very  moderate  amount  of  pressure  suffices  to 
lock  the  wheel  in  a  positive  manner.  This  construction  could  not  be 
very  well  applied  to  motor  vehicles,  because  the  action  of  the  shoe 
against  the  rubber  tire  would  be  apt  to  produce  rapid  depreciation  of 
these  costly  elements.  For  this  reason  the  brakes  of  automobiles  are 
especially  designed  so  that  they  will  wear  instead  of  producing  deteri- 
oration of  the  points  to  which  they  are  applied. 

Forms  of  Motor-Car  Brakes. — The  braking  members  generally  used 
on  automobiles  may  be  divided  into  two  classes,  each  of  these  depend- 
ing upon  *  the  property  of  frictional  adhesion  between  substances  held 
together  by  considerable  pressure.  The  usual  construction  is  to 


The  Modern  Gasoline  Automobile 


501 


attach  a  drum  to  some  portion  of  the  change-speed  mechanism,  to 
the  differential  gear  or  to  the  wheels  themselves.  At  the  present 
time  most  engineers  favor  applying  the  brakes  directly  to  the  driv- 
ing wheels,  and  pressed-steel  drums  are  usually  fastened  to  these 
members,  against  which  the  brake  acts.  The  retarding  effect  may  be 
obtained  either  by  an  internal  expanding  shoe  brake  or  by  an  external 
contracting  band  brake. 

The  principal  forms  are  outlined  at  Fig.  298.     That  at  A  con- 
sists of  an  internal  expanding  member  consisting  of  two  shoes  which 


Fig.  298. — Internal  and  External  Band  Brakes  Used  on  Motor  Car  Wheels. 

conform  to  the  arc  of  the  brake  drums.  These  are  spread  apart 
and  brought  into  forcible  contact  with  the  drums  by  means  of  a 
simple  lever  and  toggle  linkage.  Another  method  of  expanding  the 
internal  band  so  it  will  engage  the  inner  surface  of  the  drum  is  out- 


502 


The  Modern  Gasoline  Automobile 


lined  at  B.  In  this  the  toggle  linkage  is  replaced  by  a  cam  which  is 
rocked  by  the  lever  to  force  the  brake  shoes  apart  when  it  is  moved 
in  one  direction,  and  permits  them  to  close  up  and  release  the  drum 
when  it  is  rocked  the  other  way. 


-External  Brake 


Internal  Service  Brake 


Internal 
Emergency  Brake 


Fig.  299.— Typical    Automobile    Brake    Forms.      A  —  Two    Internal    Bands. 
B — Double  Expanding  Type.     C — External  and  Internal  Brake  Combination. 

The  brake  shown  at  C  consists  of  a  steel  band  which  is  lined  with 
some  friction  material  possessing  considerable  resistance  to  heat,  such 
as  asbestos-wire  fabric.  The  band  is  attached  to  a  double-bell  crank 
lever  in  such  a  way  that  it  will  be  brought  into  forcible  engagement 
with  the  external  surface  of  the  drum  if  the  end  of  the  lever  is 
moved  in  the  direction  of  the  arrow.  Another  form  of  band  brake 
is  depicted  at  Fig.  298,  D.  This  is  a  much  more  efficient  form  than 
that  outlined  at  C  and  it  has  great  holding  power.  The  band  may 


The  Modern  Gasoline  Automobile 


503 


be  adjusted  as  the  friction  material  wears,  and  thus  the  brake  may 
be  always  kept  in  perfect  adjustment. 

The  methods  in  which  the  brakes  are  usually  mounted  in  auto- 
mobiles are  clearly  shown  at  Fig.  299.  At  A  two  internal  expanding 
bands  are  mounted  inside  of  each  brake  drum,  one  pair  of  these  being 
connected  to  a  pedal  and  used  as  a  service  brake,  while  the  other  is 
attached  to  a  hand  lever  and  is  depended  upon  as  an  emergency  or 


Wheel: 


Fig.  300.— Typical  Automobile  Brake  Assembly  with  Rear  Wheel  Removed  to 
Show  Application  of  Brake  Drum  to  Wheel  and  Internal  and  External  Bands 
on  End  of  Axle. 

auxiliary  braking  member.  The  cast  shoes  are  hinged  at  their  lower 
end  and  are  faced  with  friction  material.  They  are  spread  by  means 
of  cam  expanders,  and  when  the  shoes  are  spread  apart  they  engage 


504 


The  Modem  Gasoline  Automobile 


the  inner  portion  of  the  brake  drums  with  considerable  force  and 
retard  its  motion.  The  brakes  shown  at  B  are  similar  in  operation 
to  those  outlined  at  A,  and  the  assembly  is  presented  merely  to  show 
the  relation  of  the  brake  shoes  to  the  axle  on  which  they  are  mounted. 
A  combination  of  internal  expanding  and  external  constricting  brakes 
is  shown  at  Fig.  299,  C.  This  is  a  very  common  method  of  construc- 
tion and  is  found  on  many  cars.  The  inner  brakes  are  usually  de- 
pended on  for  emergency  service,  while  the  outer  brakes,  which  may 
be  more  easily  applied,  are  used  for  braking  under  ordinary  condi- 
tions. A  common  brake  drum  serves  both  brakes,  as  the  expanding 
member  will  engage  the  inner  periphery,  while  the  external  band  will 
contract  around  the  outer  face  of  the  drum.  The  method  of  install- 
ing the  brake  on  a  typical  motor-car  rear  construction  is  shown  at 
Fig.  300. 

The  braking  members  in  automobiles  have  been  mounted  on  both 
front  and  rear  wheels,  on  the  jack  shaft  of  a  double-chain  driven  car, 


Pressure  Pins 


Ball  Bearing 


Brake  Discs 


Fig.  301.— Rear  Hub  of  Metz  Car  Showing  Multiple-Disk  Brake. 

or  on  the  propeller  shaft  of  a  bevel-  or  worm-gear  drive,  arrangement. 
Brakes  are  not  always  of  the  internal  or  external  band  form,  some 
designers  having  used  other  combinations  to  obtain  the  same  results. 
The  multiple-disk  brake  employed  on  the  Metz  car  is  shown  at  Fig. 
301.  In  this  a  series  of  disks  is  attached  to  and  revolves  with  the 
wheel  hub,  while  another  group  is  fixed  to  the  stationary  axle. 
Pressure  "is  brought  to  bear  against  one  of  the  fixed  disks  by  means 


The  Modern  Gasoline  Automobile  505 

of  pressure  pins  passing  through  one  of  the  wheel-supporting  cones, 
and  this  is  in  turn  communicated  by  each  disk  to  its  neighbor.  The 
same  object  is  attained  as  in  a  multiple-disk  clutch  and  a  larger 
amount  of  braking  surface  is  obtained  by  using  a  comparatively  large 
number  of  small  diameter  disks  instead  of  two  larger  members,  which 
might  not  have  as  much  effective  surface.  Multiple-disk  brakes  have 
been  used  to  some  extent  on  foreign  cars,  but  this  is  the  only  instance 
to  the  writer's  knowledge  where  they  have  been  applied  on  a  domestic 
product. 

Side  slipping  or  skidding  is  one  of  the  dangers  of  motoring  on 
highways  which  may  have  a  slippery  surface.  If  one  turns  the  corner 
of  a  wet  asphalt,  macadam,  or  clay  pavement  a  certain  amount  of 
side-slipping  action  will  be  evident,  and  if  the  brake  be  applied  at 
this  time  this  skidding  tendency  will  be  accentuated.  The  skidding 
tendency  of  a  self-propelled  vehicle  is  most  noticeable  when  the  brakes 
are  applied  suddenly  to  the  rear  wheels,  and  it  is  evident  by  a  swing- 
ing movement  at  the  rear  end  of  the  car  which  tends  to  bring  the 
braking  wheels  around  to  the  front  in  the  direction  in  which  the  car 
is  moving.  Various  means  have  been  proposed  to  eliminate  this  side- 
slip action,  and  numerous  forms  of  tire  chains,  studded  tire  treads 
or  treads  with  knobs  or  other  projections  of  rubber  molded  integral 
with  them  have  been  devised  to  minimize  the  skidding  tendency. 

Application  of  Front-Wheel  Brakes. — A  number  of  foreign  engi- 
neers have  applied  brakes  to  the  front  wheels  instead  of  the  rear 
members  to  reduce  the  skidding  action.  It  is  claimed  that  the  appli- 
cation of  brakes  to  the  steering  members  instead  of  the  driving  mem- 
bers will  eliminate  the  skidding  tendency,  because  the  braking  action 
would  be  on  the  wheels  which  were  already  at  the  front  end  and 
pointing  in  the  direction  in  which  the  car  was  moving.  There  are 
a  number  of  disadvantages  which  militate  against  the  general  adop- 
tion of  front-wheel  brakes,  these  being  of  a  nature  which  makes  them 
extremely  difficult  to  surmount  successfully. 

In  the  first  place,  it  is  rather  difficult  to  mount  the  brakes  on 
the  steering  knuckles  and  operate  them  from  a  fixed  portion  of  the 
car.  Then,  again,  the  usual  front  axle,  as  designed  at  the  present 
time,  is  not  adequate  to  resist  the  torsional  stresses  which  obtain 
when  the  motion  of  the  car  is  stopped  by  arresting  the  rotation  of 


506  The  Modern  Gasoline  Automobile 

the  front  wheel,  and  some  form  of  torque  member  would  have  to  be 
provided  to  take  care  of  this  strain.  This  would  mean  considerable 
mechanical  complication  which  is  not  necessary,  as  when  the  brakes 
are  applied  on  the  rear  wheels  one  common  member  may  be  used  to 
take  both  braking  and  driving  torque  stresses,  and  this  member  would 
be  needed,  even  if  the  brakes  were  applied  to  the  front  wheels,  in 
order  to  take  care  of  the  driving  torque. 

If  brakes  are  applied  to  all  four  wheels,  some  arrangement  must 
be  provided  by  which  the  front-wheel  brakes  could  be  applied  first 
to  do  away  with  the  tendency  to  skidding,  while  the  rear  brakes  would 
be  called  upon  to  add  to  the  braking  effort  already  provided.  The 
principal  difficulty  in  fitting  up  front-wheel  brakes  is  in  the  arrange- 
ment of  the  operating  parts.  These  must  be  attached  to  the  vehicle 
frame  at  one  end,  and  must  also  be  supported  on  the  axle  at  the 
other,  and  as  the  axle  is  free  to  move  relative  to  the  frame  it  will 
be  evident  that  the  problem  of  providing  a  flexible  and  positive  brak- 
ing connection  will  be  made  more  difficult  of  solution  when  one  con- 
siders that  some  provision  must  be  made  for  the  angularity  of  the 
wheels  when  turning  corners.  This  would  mean  that  the  operating 
mechanism  on  one,  side  .must  shorten,  while  that  at  the  other  side 
must  lengthen  in  some  way  to  compensate  for  the  difference  in  angu- 
larity of  the  brake  drums.  Whatever  form  of  brake  actuation  is 
used  it  must  be  designed  so  these  members  will  be  applied  with 
equal  force  and  at  the  same  time  in  each  wheel.  This  problem  is 
not  a  difficult  one  when  the  brakes  are  attached  to  the  rear  axle,  but 
it  is  not  easy  to  operate  front-wheel  brakes  in  a  positive  manner  and 
insure  that  each  will  be  applied  with  equal  force. 

Various  forms  of  front-wheel  brakes  are  shown  at  Fig.  302.  The 
design  shown  at  A  is  a  cam-expanded  shoe  which  is  mounted  on  an 
extension  of  the  steering  spindle.  The  cam  is  rocked  .by  means  of 
a  lever  attached  to  it,  which  is  moved  by  a  pin  passing  down  through 
the  steering  knuckle  bolt  and  resting  against  the  end  of  a  bell-crank 
form  of  brake  lever  carried  by  the  axle.  When  the  brake  lever  is 
moved  the  movement  of  the  end  against  which  the  pin  rests  is  trans- 
mitted to  the  cam  which  spreads  the  shoe  by  means  of  the  pin  pass- 
ing through  the  steering  knuckle.  Another  form  of  cam-expanding 
brake  is  'outlined  at  B.  In  this  the  cam  is  rocked  by  a  lever  which 


The  Modern  Gasoline  Automobile 


507 


passes  down  to  the  bottom  of  the  steering  spindle,  where  it  is  coupled 
to  the  operating  gear  by  means  of  a  steel-wire  cable  passing  around 
a  roll  at  the  end  of  the  steering-knuckle  bolt  designed  to  give  a  cer- 


Cam  Lever 


Cam 


Fig.  302.— Types  of  Front- Wheel  Brakes  that  Have  Been  Used  on  British  Auto- 
mobiles Showing  Novel  and  Ingenious  Methods  of  Brake  Actuation. 

tain  degree  of  universal  motion.     The  shoes  are  kept  from  rubbing 
against  the  inner  face  of  the  drum  by  a  coil  spring  joining  the  upper 


508  The  Modern  Gasoline  Automobile 

extremities  of  the  shoes  to  keep  them  in  contact  with  the  cam  face. 
The  brake  shoes  are  supported  at  the  bottom  in  adjustable  yokes 
which  may  be  moved  out  to  compensate  for  wear  of  the  brake-shoe 
surfaces. 

The  method  outlined  at  C  is  that  used  in  the  Argyl  (Scotch) 
motor  car.  In  this  form  the  brakes  are  operated  directly  from  the 
frame  side  instead  of  by  bell  cranks  or  wire  cables  attached  to  the 
axle.  The  brake  is  a  cam-expanded  shoe  type,. the  cam  being  moved 
by  a  brake-operating  rod,  extending  from  the  frame-side  member  to 
the  top  of  the  fixed  member  employed  to  carry  the  brake  band  which 
forms  part  of  the  steering  knuckle.  The  brake-operating  rod  is  pro- 
vided with  a  pair  of  double  ball-and-socket  universal  joints  and  is 
operated  by  means  of  a  small  lever  attached  directly  inside  of  the 
frame-side  member. 

Front-wheel  brakes  have  not  been  used  to  any  extent  on  American 
motor  cars,  but  they  have  been  applied  in  quite  a  number  of  instances 
abroad.  The  advantages  advanced  by  the  English  designers  for  this 
peculiar  form  of  brake  are  chiefly  centered  around  the  factor  of 
eliminating  skidding  and  of  being  more  accessible  and  easier  to  adjust 
than  the  rear-wheel  brakes.  Against  these  advantages  one  may  ad- 
vance the  disadvantages  of  complicated  operating  mechanism,  the 
possibility  of  unequal  braking  effort,  and  the  interference  with  posi- 
tive and  correct  steering  should  some  one  of  the  universal  operating 
rods  become  stuck  in  such  a  way  that  it  would  not  permit  the  wheel 
to  turn  as  it  should. 


CHAPTER    X 

Wheels,  Rims,  and  Tires — Wood  and  Wire  Wheels  Compared — Resilient  or 
Spring  Wheels— Advantages  of  Pneumatic  Tires — Pneumatic  Tire  Con- 
struction Outlined — Forms  of  Tire  Treads — Tire  Protectors  and  Non- 
Skid  Attachments — Demountable  Rim  Forms — Features  of  Cushion  Tires 
— Solid  Tire  Types — Tools  and  Supplies  for  Tire  Restoration — Faults  of 
Tires  and  Their  Elimination — Apparatus  for  Tire  Repairing. 

BEFORE  considering  the  forms  of  various  tires  and  rims  in  general 
use,  it  will  be  well  to  give  the  subject  of  wheel  construction  some 
consideration.  These  are  a  very  important  element  of  the  motor-car 
chassis  and  much  of  the  safety  and  comfort  of  the  occupants  of  the 
vehicle  depends  upon  the  proper  selection  of  wheels  of  sufficient  size 
and  adequate  strength.  At  the  present  time  the  wood  wheel  is  the 
most  popular  form  in  use  in  this  country,  though  abroad  considerable 
attention  is  being  paid  to  the  development  of  wire  and  metal  wheels. 

The  first  form  of  wheel  to  be  appJied  to  automobiles  was  pat- 
terned after  the  forms  used  on  bicycles,  as  it  was  thought  that  many 
of  the  same  engineering  principles  applied  equally  well  to  both  forms 
of  conveyances;  and  as  many  of  the  early  designers  and  builders  of 
motor  cars  were  formerly  in  the  bicycle  industry,  it  seems  but  natural 
that  they  should  attempt  to  apply  some  of  the  experience  gained  in 
that  field  to  the  newer  one  of  automobile  construction.  Wire  wheels 
were  soon  supplemented  by  wood  wheels  of  the  artillery  type,  because 
these  were  very  strong  and  presented  an  appearance  that  was  not  un- 
conventional because  it  did  not  differ  very  much  from  the  wheels 
generally  used  on  horse-drawn  vehicles. 

Characteristics  of  Wooden  Wheels. — Two  forms  of  wooden  wheels 
have  been  applied  to  automobile  service.  The  first  to  be  used  em- 
ployed a  Sarven  type  hub  which  did  not  prove  strong  enough,  and 
was  later  succeeded  by  the  artillery  type.  The  Sarven  wheel  is  the 
form  that  is  widely  used  on  light  carriages  and  wagons,  and  in  this 
construction  the  spokes  are  forced  into  suitable  holes  made  to  receive 

509 


510  The  Modern  Gasoline  Automobile 

them  and  held  in  a  wooden  hub,  and  the  whole  assembly  of  hub,  spokes 
and  felloe  are  held  together  by  shrinking  a  steel  tire  around  the 
assembled  wheel.  This  was  supplemented  by  some  form  of  rim 
adapted  to  take  a  rubber  tire  when  used  for  automobile  work.  The 


Fig.  303.— Wooden  Portions  of  Artillery  Type  Automobile  Wheel. 

Sarven  type  hub  did  not  prove  satisfactory  on  vehicles  of  the  self- 
propelling  form,  except  on  very  light  motor  buggies  where  the  drive 
was  by  side  chain  to  a  sprocket  attached  to  the  spokes. 

Some  attempts  were  made  to  use  this  type  of  wheel  on  live  axles 
by  driving  in,  a  metal  bushing  in  which  the  keyway  by  which  the 


The  Modern  Gasoline  Automobile 


511 


wheel  was  secured  to  the  axle  was  formed.  Considerable  trouble  was 
experienced  by  the  metal  bushings  coming  loose  in  the  hubs  and 
failing  to  drive  the  wheel.  Then,  again,  the  Sarven  t}^pe  wheel  was 
not  strong  enough  to  stand  the  side  thrusts  of  the  heavier  automobiles, 
and  was  soon  replaced  by  the  form  at  present  used,  in  which  a  metal 
hub  forms  the  center  of  the  spoke  and 
felloe  assembly. 

The  wooden  parts  of  the  artillery 
wheel  are  depicted  at  Fig.  303,  while 
the  construction  of  the  hub  can  be  very 
clearly  understood  by  referring  to 
drawings  in  preceding  chapter.  The 
ends  of  the  spokes  which  fit  between 
the  hub  flanges  are  wedge  shape  and 
are  so  formed  that  they  will  fit  closely 
together  when  assembled  to  produce  a 
complete  circle  of  wood  which  is  sand- 
wiched between  the  wheel-hub  flanges, 
held  together  by  bolts  passing  through 
them  and  the  spokes.  The  outer  end 
of  the  spokes  is  turned  down  to  fit 
holes  bored  into  the  arcs  that  com- 
prise the  felloe.  The  wheel  assem- 
bly is  held  together  in  much  the 
same  manner  as  that  employed  in 
carriage-wheel  construction,  excepting 
that  the  steel  rim  is  usually  provided 
with  hook  section  flanges  made  to 
hold  the  clincher  tire  generally  used. 
A  complete  wooden-wheel  assembly 
with  hub,  demountable  clincher  rim, 
and  pneumatic  tire  is  shown  at  Fig. 
304. 

Wire  and  Metal  Wheels. — At  the  present  time  automobile  engi- 
neers seem  agreed  that  second-growth  hickory  is  the  only  wood  that 
can  be  used  successfully  in  automobile-wheel  construction,  but  it  is 
'becoming  more  difficult  to  obtain  this  material  as  the  production  of 


Fig.  304. — Complete  Artillery- 
Wheel  Assembly. 


512  The  Modern  Gasoline  Automobile 

automobiles  is  increased.  In  England  the  wood  is  very  scarce,  so 
many  designers  in  that  country  are  returning  to  the  wire-spoke  type 
of  wheel  which  was  used  on  the  earlier  model  cars.  Suitable  wood 
for  wheels  is  not  easy  to  obtain.,  because  it  must  be  of  such  a  nature 
that  it  will  stand  both  a  steady  load  and  sudden  shocks.  Hickory 
alone  of  all  common  woods  combines  these  two  features,  and  while 
other  trees  may  furnish  lumber  that  may  be  stronger  or  tougher  than 
hickory,  in  some  applications  it  is  the  only  one  which  seems  to 
combine  the  desired  qualities.  When  the  supply  of  wood  decreases 
to  a  point  where  it  will  be  difficult  to  obtain  it  promptly,  it  is  be- 
lieved that  automobile  manufacturers  will  be  forced  to  use  metal 
wheels. 

.  This  has  been  done  by  some  of  the  producers  of  heavy  commercial 
cars  in  some  instances,  and  the  metal  wheels  which  have  been  applied 
may  be  divided  into  three  types.  Those  used  on  the  heavier  vehicles 
may  be  of  cast  steel,  having  a  spoke  and  hub  construction  very  similar 
to  that  of  the  present-day  artillery  wooden  wheels,  except  the  hubs 
and  rims  are  cast  integral  with  the  spokes.  This  forms  a  very  strong 
wheel  assembly ;  the  only  objection  that  can  be  advanced  against  them 
is  that  while  stronger  than  wooden  wheels  they  are  much  heavier. 
Metal  wheels  are  sometimes  made  by  fastening  two  steel  stampings 
together  to  form  the  rim  and  web  portions,  these  in  turn  being  joined 
to  a  separately  formed  flanged  hub  member. 

The  metal  wheel  most  generally  used,  however,  is  the  suspension 
type  so  commonly  used  in  bicycles  and  motorcycle  construction.  In 
this  the  steel  hub  member  is  joined  to  the  outer  rim  by  spokes  of 
steel  wire  interlaced  in  such  a  manner  that  they  hold  the  hub  and 
rim  together  firmly.  One  advantage  of  metal  wheels  is  that  this 
material  may  be  worked  up  into  any  desired  form,  and,  where  light- 
ness is  desired,  one  can  use  wire-spoke  wheels  and  either  the  built-up 
pressed-steel  forms  or  the  cast-steel  wheels  for  heavy  loads.  If  light- 
ness is  desired,  light  metals  which  are  very  strong  are  available, 
while  maximum  strength  is  obtained  by  the  use  of  the  highly  resisting 
materials  in  the  cast  form. 

The  wire  wheel  has  not  attained  any  degree  of  popularity  in 
America,  *but  its  gradually  widening  field  of  use  in  England  and  on 
the  Continent  shows  that  it  is  a  big  success  and  that  in  its  improved 


The  Modern  Gasoline  Automobile  513 

forms  it  has  much  to  commend  it  for  automobile  service.  The  wire 
wheel  is  lighter  than  a  wooden  wheel  of  equal  strength,  there  being 
a  saving  of  at  least  33 J  per  cent  of  weight  when  wire  wheels  are 
employed  instead  of  the  artillery  type.  Advocates  of  the  wire  wheel 
state  that  it  is  stronger  than  the  wooden  wheel  in  both  vertical  and 
horizontal  directions.  In  a  wooden  wheel  the  load  is  carried  on  the 
spokes  which  are  under  compression,  whereas  in  a  wire  wheel  the 
weight  is  carried  by  the  spokes  which  are  under  tension. 

A  series  of  tests  conducted  abroad  showed  that  wire  wheels  were 
much  stronger  and  resisted  blows  of  greater  definite  strength  applied 
to  the  rim  than  wooden  wheels  of  equivalent  rated  capacity.  It  is 
also  contended  that  wire  wTheels  are  much  more  elastic  and  resilient 
than  the  wooden  supporting  members,  and  that  a  car  equipped  with 
these  will  be  more  easy  riding  and  wear  the  tires  less  than  another 
chassis  of  the  same  weight  mounted  on  wooden  wheels.  Wire  wheels 
are  not  used  to  any  extent  on  heavy  vehicles,  and  when  metal  wheels 
are  fitted  to  trucks  they  are  usually  of  the  heavier  forms.  A  typical 
wire-wheel  assembly  is  shown  at  Fig.  305,  this  being  a  form  used  to 
a  large  extent  on  touring  vehicles  in  England. 

There  are  a  number  of  disadvantages  which  militate  against  the 
general  use  of  wrire  wheels,  the  most  serious  of  these  being  the  fact 
that  when  the  tension  of  the  spokes  is  different  the  wheel  will  go  out 
of'  shape  and  will  not  run  true.  No  matter  how  carefully  the  wheel 
is  built  up,  the  constant  shock  incidental  to  service  will  cause  some 
of  the  spokes  to  become  loose  in  the  nipples  by  which  they  are 
attached  to  the  rim.  When  these  are  tightened  up  the  entire  wheel 
must  be  gone  over  to  insure  that  all  spokes  pull  evenly  and  that  the 
hub  is  exactly  in  the  center  of  the  wheel  after  adjustments  have  been 
made.  It  is  argued  that  a  wooden  wheel  that  has  received  a  violent 
side  blow  will  be  almost  entirely  demolished,  whereas  a  wire  wheel 
subjected  to  a  similar  shock  may  be  sprung  out  of  true,  but  will 
have  sufficient  strength  to  allow  the  motorist  to  drive  the  car  to  some 
point  where  the  wheel  can  be  repaired. 

In  connection  with  this  it  may  be  stated  that  a  wooden  wheel,  if 
damaged,  may  be  repaired  by  any  blacksmith  or  wheelwright,  whereas 
a  wire  wheel  can  only  be  restored  to  its  efficient  condition  by  a  me- 
chanic skilled  in  truing  up  the  wheel.  Another  disadvantage  of 


514  The  Modern  Gasoline  Automobile 

some  moment  against  the  wire  wheel  is  that  it  is  a  very  difficult  form 
to  keep  clean,  as,  when  the  vehicle  is  washed,  the  brightly  nickeled 
spokes  must  be  wiped  off  carefully  or  they  will  rust.  This  precau 


Fig.  305.— Wire-Spoke  Automobile  Wheel  Modified   from  Bicycle  Practice. 

tion  need  not  be  taken  with  a  wooden  wheel,  as  there  is  no  multi- 
plicity of  joints  and  minute  crevices  where  dirt  or  water  may  lodge. 
Spring  and  Resilient  Wheels. — Attempts  have  been  made  to  build 
wheels  which  would  have  some  form  of  flexible  or  yielding  member 
to  join  the  rim  and  the  hub,  instead  of  the  rigid  wood  or  metal 
spokes*.  Many  spring  wheels  have  been  evolved,  the  ultimate  aim  of 
all  inventors  of  this  form  being  to  provide  a  supporting  mem! XT 


The  Modern  Gasoline  Automobile  515 

which  would  have  sufficient  resiliency  so  the  pneumatic  tire  could 
he  dispensed  with  and  the  troubles  incidental  to  its  use  eliminated. 
The  Lipkowski  spring  wheel  is  depicted  at  Fig.  306,  this  being 
a  fairly  good  example  of  the  radial  coil-spring  form  which  is  said  to 
have  given  fairly  satisfactory  results  in  its  trials.  In  this  construc- 
tion the  hub  and  felloe  are  composed  of  two  members  held  together 


Fig.  306.— Steel  Resilient  Wheel  Having  Coil  Springs  Separating  Hub  and  Rim 

Members. 

by  bolts.  These  retention  members  form  the  journals  for  the  loops 
on  the  end  of  the  spring,  while  the  spaces  between  the  outer  portions 
of  the  wheel  felloe  are  a  sufficient  distance  apart  to  act  as  a  guide 
for  the  four  solid  metal  spokes  which  are  spaced  ninety  degrees  apart 


516 


The  Modern  Gasoline  Automobile 


and  which  radiate  from  the  outer  periphery  of  the  hub  member. 
Twelve  springs  are  used,  these  being  mounted  in  sets  of  three,  each 
set  occupying  the  space  between  the  two  spokes. 

The  resilient  members  are  attached  in  such  a  manner  that  they 
are  subjected  to  alternate  compression  and  tension  loads.  Those  at 
the  top  of  the  wheel  are  under  tension,  while  those  at  the  lower 
portion  are  under  compression.  The  four  rigid  steel  spokes  engage 
suitable  projections  on  the  inside  of  the  felloe  and  are  depended  on 
to  keep  the  wheels  steady  against  side  blows  and  to  furnish  a  posi- 
tive means  of  driving  when  the  wheel  is  used  as  a  traction  member. 
The  disadvantage  of  this  type  of  construction  is  that  the  springs  are 
liable  to  break  and  that  the  construction  is  very  heavy  when  com- 
pared to  wooden  wheels.  It  is  claimed  that  this  type  of  wheel  is 
fifty  per  cent  heavier  than  an  ordinary  wooden  wheel  of  greater 
strength.  Another  disadvantage  of  spring  wheels  of  this  pattern  i> 
that  they  are  apt  to  be  noisy  in  action,  which  is  not  desirable. 


Fig.  307. — Spring  Wheels  Designed  to  Provide  a  Resilient  Support  for  Automo- 
biles without  Using  Pneumatic  Tires, 

Two  other  forms  of  spring  wheels  are  shown  at  Fig.  307.  That 
at  A  employs  a  series  of  radial  compression  springs  which  provide 
the  resilient  feature,  while  the  strength  is  obtained  by  means  of  the 
plungers  fastened  to  the  upper  member  which  is  attached  to  the 
wheel  Tim;  these  in  turn  fit  the  cylinders  attached  to  the  outer 
periphery  of  the  inner  wheel.  The  spring  serves  to  keep  these  mem- 


The  Modern  Gasoline  Automobile  517 

bers  separated  at  all  times.  In  the  construction  outlined  at  B  the 
spokes  are  flat  springs,  curved  in  a  peculiar  manner,  and  join  the 
central  hub  member  with  the  outer  rim.  Neither  one  of  the  forms 
shown  have  been  adapted  practically,  and  the  illustrations  are 
presented  merely  to  show  freak  constructions  which  have  but  little 
practical  value. 

It  may  be  said  of  all  forms  of  spring  wheels  that  their  disad- 
vantages are  of  sufficient  magnitude  to  make  those  which  are  advanced 
against  the  pneumatic  tire  seem  simple  by  comparison.  While  pneu- 
matic tires  may  fail  on  the  road,  they  may  be  easily  restored  or 
repaired  and  the  journey  continued  with  but  little  interruption.  If 
members  of  a  spring  or  resilient  wheel  should  fail  in  service  the  work 
of  replacement  would  entail  a  degree  of  mechanical  skill  not  usually 
possessed  by  the  average  motorist.  Many  inventors  have  given  this 
problem  considerable  attention,  but  it  is  safe  to  say  that  the  rubber 
tire  in  either  of  its  forms  is  absolutely  necessary  to  successful  motor- 
vehicle  operation,  and  that  there  is  but  little  future  for  resilient 
wheels  depending  on  springs  or  other  metal  resilient  members  to 
cushion  the  shocks  met  with  when  traveling  over  ordinary  highways. 

Forms  of  Automobile  Tires. — The  wheels  of  automobiles,  with  but 
few  exceptions,  are  provided  with  rubbed  tires.  The  simplest  is  a 
solid  band  of  rubber  composition;  next  in  order  we  have  the  various 
forms  of  cushion  tires  in  which  the  band  of  rubber  is  perforated  with 
a  number  of  small  holes  or  provided  with  a  series  of  openings  de- 
signed to  provide  greater  resiliency  and  make  the  tire  more  yielding 
than  the  solid-rubber  form.  Solid  tires  are  invariably  adapted  to 
industrial  conveyances. 

The  most  common  form  of  tire,  and  that  generally  used  on  auto- 
mobiles, is  composed  of  a  hollow  rubber  tube  of  circular  section  rilled 
with  air  and  protected  from  wear  by  means  of  an  outer  shoe  or 
casing.  The  use  of  air  under  compression  provides  a  very  resilient 
medium  for  supporting  the  vehicle,  and  of  the  various  forms  of  rub- 
ber tires  the  pneumatic  form  is  the  one  that  is  the  most  desirable. 
The  development  of  the  modern  automobile  may  be  attributed  largely 
to  the  advances  made  in  pneumatic-tire  construction,  as  these  mem- 
bers made  it  possible  to  drive  automobiles  at  high  speed  over  rough 
road  surfaces  without  stressing  the  mechanism  or  causing  discom- 


518  The  Modern  Gasoline  Automobile 

fort  of  the  passengers.  While  solid-rubber  tires  and  members  of  the 
cushion  form  have  a  certain  degree  of  elasticity,  they  do  not  ride  as 
easy  as  pneumatic  tires,  because  rubber  cannot  be  compressed,  but 
only  distorted.  Solid-rubber  and  cushion  tires  are  suitable  where 
vehicle  speeds  are  low,  but  are  very  unsatisfactory  for  automobiles 
traveling  at  speeds  over  fifteen  miles  per  hour. 


B 


Fig.  308.— Comparison  of  Action  of  Pneumatic  and  Solid-Rubber  Tires  when 
Wheel  Rides  Over  Obstacle. 

A  comparison  between  the  action  of  pneumatic  and  solid-rubber 
tires  is  made  at  Fig.  308  so  the  superiority  of  the  latter  form  may 
be  readily  understood.  At  A,  a  wheel  shod  with  a  pneumatic  tire 
is  shown  in  contact  with  an  obstacle  in  the  road.  When  the  wheel 


The  Modern  Gasoline  Automobile  519 

passes  over  this  obstruction,,  the  walls  of  the  tire,  which  are  rela- 
tively light,  will  deflect  inward  and  compress  the  air  inside  of  the 
tires.  The  wheel  is  not  raised  from  the  ground  and  the  vehicle 
rides  over  the  obstruction  without  any  appreciable  upward  movement 
or  throw  of  the  chassis.  At  B  a  solid  rubber  tire  is  shown  passing 
over  the  same  obstacle.  In  this  case  the  composition  is  so  stiff  that 
it  will  not  bend  in  and  the  wheel  is  raised  from  the  ground.  This 
throws  the  vehicle  body  upward,  jarring  both  mechanism  and  pas- 
sengers. The  severity  of  the  jolt  augments  proportionately  to  the 
speed  of  the  vehicle.  It  will  be  patent  that  the  form  of  tire  depicted 
at  A,  which  permits  the  stone  to  imbed  itself  into  the  tire,  will  be 
much  more  easy  riding  than  that  form  which  will  ride  over  the 
obstacle.  The  great  advantage  of  a  pneumatic  tire  is  that  it  will 
give  more  than  ordinary  elasticity  to  the  wheel  and  will  absorb 
most  of  the  minor  shocks  that  would  be  transmitted  to  the  springs 
of  the  vehicle  if  noncompressible  tires  were  used. 

Construction  of  Pneumatic  Tires  Defined. — The  pneumatic  tire  of 
the  present  day  is  invariably  of  the  double-tube  type  and  is  com- 
posed of  two  members,  the  inner  tube  and  the  shoe  or  carcass.  The 
inner  member  is  utilized  to  retain  the  air  and  is  made  of  a  very  pure 
rubber,  about  an  eighth  of  an  inch  thick  ^or  cars  of  average  weight. 
While  this  tube  is  very  elastic  and  is  air-tight,  it  would  not  be  strong 
enough  or  have  adequate  resistance  to  be  run  directly  in  contact 
with  the  road  surface;  therefore  it  is  necessary  to  protect  it  by  a 
shoe  composed  of  layers  of  fabric  and  rubber  composition.  The  shoe 
member  is  provided  with  beads  on  its  inner  periphery  designed  to 
interlock  with  the  rim  channel,  as  shown  at  Fig.  309. 

The  main  portion  of  the  outer  casing  is  composed  of  five  or  more 
layers  of  a  Sea  Island  cotton  fabric  "  frictioned "  with  high-grade 
rubber  composition.  This  is  forced  into  the  mesh  of  the  cloth  by 
machinery  so  the  fabric  will  be  practically  waterproof  and  will  join 
intimately  with  the  other  plies  by  a  process  of  vulcanization  when 
the  shoe  is  cured.  Outside  of  the  fabric  body  a  layer  of  very  resilient 
rubber,  approximately  of  crescent  form,  known  as  the  padding,  IB 
provided  to  give  a  certain  degree  of  elasticity  to  the  shoe.  Between 
this  member  and  the  tread  a  number  of  pieces  of  heavy  fabric  called 
"  breaker  strips  "  are  interposed  to  offer  a  certain  degree  of  resistance 


Tread 


Padding 


Breaker  Strips 


Bead  Filler 


Bead 


Felloe 


Rim  Channel 


Valve  Inside 


Valve  Cap 


Fig.  309.— Outlining  Construction  of  Pneumatic  Automobile  Tire  Fitted  to  Sim- 
ple Clincher  Run. 
520 


The  Modern  Gasoline  Automobile 


521 


to  any  sharp  object  that  might  penetrate  the  tread  and  go  through 
the  padding  and  into  the  fabric  body  if  the  breaker  strips  were  not 
interposed  to  deflect  the  puncturing  object  to  one  side. 


-Threads  for  Cap 

Rubber  Packi 
-Valve  Seat 
Air  Ven 


Spring- 


Valve  Stem 


-Valve  Stem  Guide 


-Tire  Valve  Stem 


Valve  Closed 


Valve  Open 


Fig.  310.— Construction  of  Schrader  Universal  Tire  Valve. 

The  tread  is  the  part  of  the  tire  that  is  subjected  to  the  greatest 
stress,  as  it  must  resist  the  abrading  influence  of  the  road  and,  when 


522  The  Modern  Gasoline  Automobile 

the  tire  is  used  on  the  rear  wheels,  the  wearing  effect  of  the  friction 
produced  by  the  tractive  effort  which  exists  at  the  point  of  contact 
between  the  driving  member  and  the  ground.  The  tread  is  of  very 
tough  rubber  composition  and  differs  from  the  material  used  as 
padding  or  for  the  inner  tube  in  that  it  does  not  possess  a  very  great 
degree  of  elasticity.  This  quality  is  sacrificed  for  that  of  greater 
strength  and  resistance  to  wear,  which  is  more  essential  at  this 
point. 

The  air  is  introduced  into  the  tire  through  a  simple  form  of 
automatic  valve  which  is  securely  attached  to  the  inner  tube.  As 
the  inner  tube  becomes  distended  by  the  air  pumped  into  it,  it  forces 
the  beads  of  the  tire  outward  and  clinches  the  shoe  so  firmly  in  the 
rim  channel  that  it  will  be  impossible  to  dislodge  it  without  the  use 
of  special  tire  irons,  and  then  only  when  the  air  pressure  is  relieved 
from  the  inner  tube.  A  detailed  view  of  the  valve  stem  in  the  open 
and  closed  position  is  shown  at  Fig.  310,  and  the  construction  of 
this  simple  fitting  can  be  easily  understood.  The  valve  is  held  against 
its  seat  by  a  tension  spring  and  will  only  open  when  the  valve  stem 
is  depressed  by  the  hand  or  from  the  pressure  of  the  air  forced 
against  it  when  it  is  desired  to  inflate  the  tire.  While  the  air  pressure 
from  the  pump  will  be  sufficient  to  force  the  valve  from  its  seat,  the 
air  pressure  from  the  inside  of  the  tire  only  serves  to  hold  it  more 
firmly  in  place. 

Pneumatic  tires  are  not  always  of  the  clincher  form.  Various 
other  constructions  have  been  devised,  some  to  facilitate  a  more  ready 
removal  than  the  clincher  construction  permits,  while  others  have 
been  designed  to  make  for  a  more  secure  attachment  by  some  me- 
chanical means.  Various  forms  of  quick-detachable  rims  and  the 
tires  adapted  for  use  with  them  are  shown  at  Fig.  311.  In  the 
ordinary  clincher  tire  it  is  necessary  to  force  the  bead  over  the  chan- 
nel when  it  is  desired  to  remove  the  outer  casing,  and  while  this  can 
be  accomplished  with  comparative  ease  on  the  smaller  tires,  it  is  very 
difficult  to  remove  or  apply  large  clincher  tires.  In  the  form  shown 
at  A  the  clincher  rim  is  made  in  two  parts,  one  of  the  sections  being 
easily  removable  when  the  locking  ring  is  taken  out  of  the  groove 
in  which  dt  fits.  When  the  movable  section  of  the  rim  is  taken  off 
the  outer  casing  may  be  easily  removed,  as  it  can  be  slipped  off 


The  Modern  Gasoline  Automobile 


523 


the  fixed  portion  of  the  rim  just  as  a  belt  can  be  removed  from  a 
pulley. 

The  Dunlop  type  of  outer  casing  is  depicted  at  B  and  C,  these 
also  being  fitted  to   quick-detachable  rims.     In  the   Dunlop   casing 


Fig.  311.— Forms  of  Quick-Detachable  Rims  which  Permit  Easy  Removal  of 

Pnematic  Tires. 


retention  is  by  a  series  of  steel  wires  at  the  base  of  the  tire  which  have 
a  certain  amount  of  holding  power,  which  is  further  augmented  by 


524  The  Modern  Gasoline  Automobile 

the  air  pressure  inside  of  the  tube.  It  is  claimed  for  this  construc- 
tion that  it  is  more  easily  removed  than  the  clincher  tire  when  applied 
to  a  one-piece  rim,  though  on  the  quick-detachable  type  shown  in 
illustration  one  form  is  as  easily  removed  as  the  other.  The  rim 
shown  at  A  and  B  is  the  same  member,  and  it  will  take  either  clincher 
or  Dunlop  type  casing.  When  used  for  the  latter  a  rubber  filler 
ring  is  provided  to  fill  the  channel  of  the  fixed  portion  of  the  rim, 
while  the  flat  side  of  the  removable  portion  is  brought  in  contact 
with  the  casing  walls  instead  of  the  channel  or  hooked  side.  The 
form  shown  at  C  is  made  exclusively  for  use  with  Dunlop  type 
casings,  and  cannot  be  utilized  for  clincher  tires. 

At  D  the  Fisk  bolted-on  casing  is  shown.  This  differs  from  the 
other  forms  in  that  the  clinchers  are  designed  in  such  a  manner  that 
they  practically  form  a  foot  or  base,  and  when  closed  together  will 
keep  the  inner  tube  away  from  the  rim,  which  is  not  done  with  the 
other  forms  of  rims.  The  rim  proper  consists  of  a  flat  band  of  steel 
attached  to  the  wheel  felloe.  Two  locking  rings  are  provided,  one 
at  either  side  of  the  tire,  and  these  are  held  into  proper  relation  and 
clamped  tightly  against  the  base  member  of  the  shoe  by  means  of 
bolts  which  pass  through  the  enlarged  beads  of  the  casing.  This 
form  of  attachment  is  very  secure  and  the  tire  is  held  to  the  rim  by 
mechanical  means  as  well  as  air  pressure.  In  other  forms  of  tires 
in  which  air  pressure  alone  is  depended  upon  to  keep  the  beads  in 
contact  with  the  rim  it  is  possible  for  tires  to  be  thrown  off  the 
wheels  if  they  become  deflated,  though  with  the  mechanically  fastened 
form,  as  shown  at  D,  the  tire  will  be  held  in  place,  even  when  par- 
tially deflated,  much  more  securely  than  in  the  other  forms. 

The  construction  of  inner  tubes  is  practically  the  same  in 
all  standard  makes  of  tires,  and  these  are  usually  interchangeable. 
The  outer  casings  differ  in  some  respects,  these  being  merely  a  matter 
of  detail  involving  the  number  of  plies  of  fabric,  the  thickness  of  the 
padding,  the  arrangement  of  breaker  strips,  and  the  character  of 
the  tread.  All  the  tires  shown  at  Fig.  311  have  the  plain  round 
tread,  which  is  the  most  satisfactory  for  all-around  use.  The  smooth 
tread,  however,  has  the  disadvantage  in  that  it  is  liable  to  slip  on 
muddy  roads,  and  for  this  reason  a  number  of  tread  forms  have  been 
designed  to  secure  greater  adhesion  to  the  road  or  to  reduce  wear. 


The  Modern  Gasoline  Automobile 


525 


A  round-tread  tire  will  wear  off  until  the  breaker  strips  are  exposed, 
and  the  tire  should  be  retreaded  as  soon  as  this  condition  is  apparent. 
The  casings  shown  at  Fig.  312  are  a  few  of  the  forms  which 
have  been  designed  to  secure  greater  wear  of  the  tread.  In  that 
shown  at  A  the  tread  is  raised  at  five  portions  and  is  very  thick.  In 
that  shown  at  B  the  tread  is  provided  with  a  large  number  of  small 


Fig.  312. — Showing  Various  Raised  Treads  Used  on  Pneumatic  Tire  Casings. 

rubber  studs  or  projections  which  are  depended  on  to  prevent  side 
slip  more  than  providing  any  great  amount  of  added  wear  to  the 
tread.  The  form  shown  at  C  is  known  as  a  raised-tread  type,  and 
in  this  the  round  tread  is  reenforced  with  a  flat  band  running  around 
the  outer  periphery,  this  providing  a  greater  thickness  of  tread  than 
will  be  possible  with  the  round-tread  construction. 

The  leading  forms  of  treads  designed  to  secure  greater  traction 
than  that  obtained  from  the  plain-tread  forms  are  shown  at  Fig.  313. 
In  the  Morgan  &  Wright,  shown  at  A,  a  large  number  of  knobs  are 
molded  integral  with  the  tread  to  prevent  skidding.  The  Empire 
casing  shown  at  B  has  a  number  of  disks  composed  of  strips  of  fabric 
rolled  up  and  set  edgewise  in  the  tread  to  promote  adhesion.  In  the 
Swinhart,  which  is  depicted  at  C,  strips  of  rubber  are  molded  with 
the  tread  to  form  a  species  of  basket  weave.  This  prevents  skidding, 
because  the  spaces  between  the  strips  will  fill  with  mud  or  dirt  and 
will  not  slip  over  the  road  surface  as  readily  as  a  smooth  tread.  The 
casing  shown  at  D  is  provided  with  a  number  of  rings  molded  with 
the  tread  to  form  little  cups  which  grip  the  road  by  the  suction  effect 


526  The  Modern  Gasoline  Automobile 

of  the  air  compressed  between  the  tire  and  the  road  surface  in  the 
depressions.  The  Ajax  nonskid  tread  depicted  at  E  is  composed  of 
diamond-shaped  rubber  pieces  molded  integral  with  the  tread  when 
the  tire  is  cured.  A  very  ingenious  method  of  roughening  the  sur- 
face of  the  tread  to  promote  traction  is  that  used  on  the  Fire- 
stone casings.  In  this  the  words  "  Firestone "  and  "  Non-Skid " 
are'  molded  in  bold  lettering  alternately  and  at  an  angle  all  around 
the  shoe. 

The  Harford  Midgeley  tread  is  depicted  at  G.  This  construc- 
tion has  a  series  of  coil  springs  molded  around  the  outer  periphery 
of  the  casing.  The  Diamond  casing  outlined  at  H  utilizes  the  Bailey 
rubber-stud  tread,  one  of  the  first  antiskidding  treads  to  be  devised. 
In  the  Michelin  casing  illustrated  at  I,  a  leather  band  provided  with 
steel  studs,  which  are  riveted  through  it  and  the  casing,  is  depended 
on  to  prevent  skidding,  to  secure  improved  traction,  and  to  make 
the  casing  practically  puncture  proof  from  ordinary  road  obstacles. 
The  Republic  Staggard  tread  tire  is  shown  at  J.  The  principle  of 
providing  a  large  number  of  projections  which  is  used  in  the  forms 
depicted  at  A,  D,  H,  I,  is  followed  on  this  casing  as  well,  but  these 
knobs  are  of  such  size  the  liability  of  rapid  wear,  which  is  present 
when  rubber  buttons  of  comparatively  small  size  are  used,  is  reduced 
and  the  life  and  antiskidding  properties  of  the  tread  are  augmented 
proportionately. 

While  the  nonskidding  forms  of  tires  have  peculiar  advantages 
which  adapt  them  for  use  on  soft  and  slippery  roads,  they  are  more 
expensive  than  the  round-tread  casings,  and  are  really  not  needed  a 
large  part  of  the  time.  The  labor  of  changing  from  the  antiskid  type 
of  tread  to  smooth  casings  would  be  considerable,  and  it  would  not 
be  practical  to  make  the  changes  as  often  as  conditions  imposed  by 
our  variable  climate  would  make  necessary.  For  this  reason  a  num- 
ber of  auxiliary  treads  and  nonskid  devices  have  been  placed  on  ^  the 
market,  the  idea  being  to  use  these  in  conjunction  with  the  plain- 
tread  tires  when  necessary.  These  auxiliaries  may  be  divided  into 
two  classes.  First,  those  designed  merely  to  promote  better  tractive 
effort  and  eliminate  skidding,  and,  secondly,  those  which  have  been 
designed\to  act  as  a  protector  for  the  casing  of  rubber  which  they 
encircle. 


30°0  O  O  O  O  C 


527 


528  The  Modern  Gasoline  Automobile 

A  number  of  these  auxiliaries  are  shown  at  Fig.  314.  That  at 
A  is  a  leather  tread  provided  with  steel  studs  on  the  tread  surface, 
made  in  such  a  form  that  it  is  put  around  the  tire  when  the  casing 
is  deflated  and  held  firmly  in  place  by  blowing  up  the  tire  again. 
This  may  be  classed  with  the  tire  protectors,  as  it  is  believed  the 
heavy  chrome-leather  band  has  much  more  resistance  to  nails  or 
other  objects  which  might  puncture  the  rubber  tube,  than  the  plain 
round-tread  tire  would  have.  At  B  and  C  devices  which  belong  to 
the  first  class  are  depicted.  These  consist  of  cross  chains  attached 
to  suitable  side  members  which  encircle  the  wheels.  The  object  of 
the  chains  on  the  tire  tread  is  to  eliminate  loss-power  effort  by  pro- 
viding a  better  grip  between  the  wheels  and  road  surface,  and  not  to 
act  as  a  protector  for  the  outer  casing  except  in  a  somewhat  limited 
way.  In  the  form  shown  at  B  the  cross  chains  are  attached  in  such 
a  manner  that  they  lie  in  the  same  plane  as  do  the  rungs  of  a  ladder. 
At  C  the  chain  members  are  of  zigzag  form.  The  protectors  shown 
at  D,  E,  and  F  are  very  similar  in  principle  to  that  outlined  at  A, 
except  that  the  method  of  securing  them  to  the  wheel  varies  to  a 
slight  extent.  That  at  D  is  a  form  designed  to  encircle  the  casing 
and  can  be  held  in  place  by  the  air  pressure  inside  of  the  tire.  At  E 
the  protector  is  fastened  to  the  wheel  by  a  series  of  strap  members 
which  clinch  under  a  side-retaining  ring  member.  At  F  the  edges 
of  the  protector  are  provided  with  hooks  which  grip  the  flanges  of 
the  clincher  tire  and  thus  hold  the  protector  very  firmly  in  place 
when  the  tire  is  properly  inflated  and  the  casing  distended. 

The  disadvantage  of  tire  protectors  is  that  they  decrease  the 
resiliency  of  the  tire,  because  leather  is  not  as  flexible  as  rubber, 
especially,  after  it  has  become  hard  by  exposure  to  water.  The  use 
of  these  protectors  undoubtedly  conserves  the  tire  casing  from  punc- 
ture, but  considerable  heat  is  generated  between  the  tire  and  the 
protector,  and  this  may  be  sufficiently  high  to  weaken  the  rubber 
casing.  Most  motorists  favor  the  use  of  the  quick-detachable  chains 
to  prevent  skidding,  because  these  may  be  easily  removed  when  they 
are  not  needed.  There  is  some  labor  involved  in  removing  and  re- 
placing the  leather  protectors,  and  these  are  not  usually  used  with 
new  casings  on  account  of  the  decrease  of  tire  resiliency.  They  are 
often  applied  to  weak  casings  or  shoes  which  have  been  worn  to  the 


The  Modern  Gasoline  Automobile 


529 


Fig.  314. — Supplementary  Treads  and  Anti-Skidding  Attachments  Designed  to 
Use  in  Connection  with  Smooth-Tread  Casings. 


530 


The  Modern  Gasoline  Automobile 


73 
0> 

<r> 
£ 

bfl 


I 


fabric,  and  when  used  in 
this  manner  they  are  very 
useful  in  securing  greater 
service  from  the  weak 
tires,  which  would  have 
to  be  discarded  if  some 
form  of  protecting  tread 
was  not  used. 

The  views  at  Fig.  315 
show  the  ease  with  which 
Weed  chain  grips  can  be 
attached  to  the  wheel.  In 
the  view  shown  at  A  the 
chain  has  been  applied  to 
the  tire  and  the  vehicle 
has  been  pushed  forward 
just  enough  to  ride  over 
the  loose  ends  of  the 
chain,  which  are  on  the 
ground.  At  B  the  car 
has  been  pushed  forward 
sufficiently  so  the  loose 
ends  of  the  chain  are 
clear  of  the  wheel,  and 
the  process  of  hooking  up 
by  means  of  little  snap 
hooks  is  easily  performed, 
as  outlined  at  C. 

Demountable    Rim 
Forms. — The    advantages 
of   the   quick  -  detachable 
rim    over    the    ordinal 
clincher    pattern    havi 
been    previously    consi( 
ered.      It    will    be    seei 
that  it  is  possible  to  re- 
move a  tire  with  less  dif- 


The  Modern  Gasoline  Automobile  531 

ficulty  than  is  present  when  the  clincher  rims  are  used.  While  a 
defective  tire  may  be  removed  and  replaced  with  a  new  one  very 
easily,  it  is  necessary  to  inflate  the  new  tire  with  air  by  means  of  a 
hand  or  power  pump  or  with  carbonic-acid  gas  carried  under  pressure 
in  a  portable  gas  tank.  In  order  to  reduce  the  time  occupied  in 
changing  tires,  which  is  needed  to  adjust  the  shoe  properly  and  blow 
up  the  inner  tube,  a  number  of  demountable  rims  have  been  devised. 
The  wheel  felloe  carries  a  metal  rim,  and  to  this  is  attached  a  second 
member  on  which  the  tire  is  mounted.  The  tire-carrying  rim  may 
be  securely  attached  to  the  wheel  by  means  of  suitable  and  quickly 
operated  clamping  bolts  or  rims. 

When  demountable  rims  are  fitted  instead  of  carrying  the  usual 
spare  outer  casing,  fully  inflated  tires  are  carried  on  rims  similar  to 
the  demountable  portions,  and  when  the  tire  is  punctured  the  dam- 
aged one  and  its  rim, are  removed  as  a  unit 'and  a  new,  fully  inflated 
member  replaced.  When  it  is  necessary  to  remove  the  shoe,  as  in 
the  ordinary  single-rim  construction,  the  operation  of  replacing  a 
tire  will  take  from  ten  to  fifteen  minutes  under  favorable  conditions, 
but  with  quick-demountable  rims  the  operation  of  changing  a  tire 
will  take  only  two  or  three  minutes.  Demountable  rims  are  more 
expensive  than  the  simpler  forms,  but  the*  convenience  and  elimina- 
tion of  time-consuming  delay,  as  well  as  the  saving  in  labor,  more 
than  compensates  for  the  increased  cost  of  equipment. 

Numerous  forms  of  demountable  rims  have  been  devised,  but 
few  have  survived  the  test  of  time  and  have  received  general  appli- 
cation. At  Fig.  316  a  combination  of  quick-detachable  and  demount- 
able rims  is  shown.  With  this  construction  the  advantages  of  both 
types  are  obtained  without  disadvantages  of  any  moment,  excepting 
those  of  cost  of  equipment.  The  quick-detachable  type  of  rim  makes 
it  possible  to  change  the  tires  very  easily,  should  this  be  necessary, 
and  makes  for  more  easy  removal  for  repairing  when  the  damaged 
tires  are  restored  to  their  efficient  condition.  In  this  form  the  tire- 
carrying  rim  is  held  on  the  felloe  band  by  a  clamping  collar  mounted 
on  the  stud  and  forced  in  place  by  a  nut  on  the  outer  end  of  the 
stud.  The  construction  is  so  clearly  shown  that  its  advantages  will 
be  readily  understood. 

The  clincher  type  of  rim  has  been  used  on  many  cars  because  it 


532 


The  Modern  Gasoline  Automobile 


has  been  a  standard  fitting  for  a  number  of  years,  but  at  the  present 
time  it  is  seldom  used  in  connection  with  large  tires,  which  are 
difficult  to  remove  from  the  wheels  unless  used  in  combination  with 
a  demountable  rim.  A  number  of  standard  demountable  rims  whicli 
have  received  general  application  are  shown  at  Fig.  317.  That  at 
A  holds  the  clincher  rim  which  carries  the  tire  in  place  by  a  series 
of  clamps  and  wedges  which  are  forced  against  the  tire-carrying  rim 


Tire  Carrying  Rim 

Felloe  Band 


Collar 


Felloe 


Bolt 


STANDARD  DEMOUNTABLE 


Fig.  316. — Quick-Detachable  Rim  of  the  Demountable  Form. 

by  pressure  of  nuts  carried  at  the  end  of  bolts  passing  through  the 
wheel  felloe  and  having  peculiarly  shaped  heads,  which  prevent  the 
tire-carrying  rim  from  moving  over  the  inner  edge  of  the  wheel.  A 
number  of  these  bolts  are  provided,  the  spacing  varying  with  the 
weight  of  car  and  size  of  tire.  On  light  cars  one  bolt  to  every  two 
spokes  is  considered  ample,  while  on  heavier  vehicles  a  bolt  may  be 
used  between  every  two  spokes,  which  would  mean  that  there  would 
be  as  many  clamping  bolts  used  as  there  were  spokes  in  the  wheel. 

The  form  outlined  at  B  is  similar  in  construction  to  that  outlined 
at  A,  except  that  the  felloe  band  is  a  substantial  member  whicli  does 
not  need  to  be  reenforced  to  hold  the  tire-carrying  clincher  rim 
firmly  in  place  when  the  clamps  are  screwed  home  by  the  nuts.  The 
Fisk  demountable  rim,  used  in  connection  with  the  Fisk  bolted-on 
type  o£  detachable  tire,  as  shown  at  Fig.  311,  D,  is  outlined  in  section 
at  Fig.  317,  C.  In  this  a  portion  of  the  felloe  is  chamfered  off  and 


533 


534  The  Modern  Gasoline  Automobile 

the  felloe  band  is  made  to  fit.  The  tire-carrying  rim  is  locked  in 
place  by  a  wedge  member  that  slides  on  the  angular  side  of  the  felloe 
band  when  pressure  is  brought  to  bear  upon  its  face  by  the  nuts 
carried  at  the  end  of  the  bolts  passing  through  the  felloe  and  felloe 
band.  As  the  wedge  rides  up  on  the  incline  it  locks  the  tire-carrying 
rim  firmly  in  place  and  prevents  either  lateral  or  circumferential 
displacement. 

In  the  construction  depicted  at  D  a  tire-carrying  rim  of  the 
clincher  type  is  used,  and  this  in  turn  is  attached  to  a  ring  member 
which  has  chamfered  corners.  The  felloe  band  has  two  inclines,  one 
designed  to  rest  against  one  side  of  the  chamfered  ring,  while  the 
other  acts  as  a  seat  for  the  wedge-shape  locking  ring,  which  is  forced 
in  place  under  the  tire-carrying  rim  by  means  of  clamps  and  nuts. 
In  order  to  make  for  quick  removal,  a  wrench  of  the  socket  type  is 
usually  attached  to  a  bit  brace,  such  as  used  by  carpenters,  for  loosen- 
ing and  tightening  and  clamping  nuts.  With  some  forms  of  de- 
mountable rim  it  is  necessary  to-  remove  the  nut  entirely  in  order  to 
slip  the  clamp  off  the  bolt.  In  others  the  nuts  are  merely  loosened 
and  the  clamps  either  swung  or  dropped  out  of  the  way  of  the  tire- 
carrying  rim,  which  is  easily  slid  off  the  felloe  band.  Other  forms 
of  demountable  rims  have  been  devised  in  which  the  tire-carrying 
member  is  held  in  place  by  some  form  of  expanding  bands  which  is 
made  to  increase  its  diameter  by  means  of  wedges  or  cam  action,  but 
these  are  not  so  generally  used  as  the  types  described. 

Features  of  Cushion  Tires. — Some  classes  of  vehicles  that  are  not 
designed  to  run  at  high  rates  of  speed,  and  which  are  not  intended  to 
carry  heavy  loads,  are  fitted  with  cushion  tires.  While  these  do  not 
have  the  resiliency  of  the  pneumatic  form,  they  have  much  greater 
flexibility  than  solid-rubber  tires.  For  this  reason  they  are  sonic- 
times  used  on  the  electrically  propelled  light  delivery  or  pleasure 
vehicles  and  sometimes  on  the  light-weight  commercial  cars  of  the 
gasoline  type.  Some  of  the  popular  forms  of  cushion  tires  are  showi 
at  Fig.  318.  At  A  the  tire  tread,  which  is  of  the  dual  form,  is  moldc 
in  such  a  manner  that  a  series  of  shallow  grooves  are  formed  aroum 
the  tire.  These  incline  from  the  outside  toward  the  center  and  MH> 
depended  on  to  give  improved  traction  as  well  as  to  make  the  tire 
more  resilient.  The  base  of  the  tire  is  pierced  with  a  large  number 


The  Modern  Gasoline  Automobile 


535 


of  holes  which  extend  clear  through  from  side  to  side,  so  the  outer 
tread  or  load-carrying  portion  is  supported  on  a  series  of  rubber 
bridges  which  are  adapted  to  bend  and  provide  a  certain  degree  of 
flexibility. 

The  cushion  tire  shown  at  B  is  similar  in  form  to  the  conven- 
tional clincher  casing,  and  is  designed  to  be  used  on  clincher  rims 


Fig.  318. — Cushion  Tires  which  Provide  More  Resiliency  than   Solid-Rubber 
Types  but  are  Not  Equal  to  the  Pneumatic  Forms. 

of  the  pattern  commonly  supplied  with  pneumatic  tires.  The  flexible 
feature  of  this  tire  is  obtained  by  using  a  number  of  rubber  load- 
supporting  partitions  to  join  the  walls  of  the  tire,  and  at  the  same 
time  they  are  separated  from  each  other  by  an  air  space  of  sufficient 
size  so  the  tire  will  distort  more  easily  than  the  conventional  solid- 
rubber  pattern.  The  cushion  tire  shown  at  C  depends  upon  the  form 
of  tread  to  provide  resiliency,  and  it  would  not  be  as  flexible  as 
either  of  the  two  forms  previously  considered. 

One  objection  to  either  solid  or  cushion  tires  is  that  a  deep  cut 
or  stone  bruise  will  seriously  weaken  the  entire  structure,  whereas 
only  a  limited  portion  is  really  unfit  for  use.  Then  again,  sometimes, 
when  brakes  are  locked  too-  suddenly,  a  portion  of  the  tire  may  be 


536 


The  Modern  Gasoline  Automobile 


worn  more  than  the  other  parts,  but  the  entire  efficiency  of  the  tire 
will  be  affected  and  the  strength  will  depend  upon  that  of  the  weakest 
portion.  The  sectional  cushion  tire  which  is  depicted  at  Fig.  319,  A, 
has  been  evolved  to  make  possible  the  replacement  of  one  or  more 
injured  portions  without  disturbing  the  other  members.  The  tire 
is  composed  of  a  series  of  hollow  rubber  segments,  as  shown,  which 


Solid  Rubber  Tread 


.Dovetail 


Tire  Bead 


Securing  Washers       / 

Sealins  Washers        /        Wooden  Felloe 
Steel  Rim 


Clamping  Bolt 


Fig.  319.— Novel  Forms  of  Cushion  Tires.  A— Cairns  Detachable  Segment 
Construction.  B — Combination  Form  Comprising  Heavy  Tread  and  In- 
flatable Inner  Tube. 

are  held  securely  in  place  by  means  of  a  dovetail  structure  which 
extends  from  the  face  of  one  segment  to  engage  with  a  corresponding 
member  on  one  of  the  faces  of  the  neighboring  segment.  These  are 
securely  fastened  to  the  wooden  felloe  of  the  wheel  and  into  the  steel 
rim  by  means  of  bolts  and  washers.  A  certain  amount  of  air  is 
retained  in  the  spherical  chambers  of  the  rubber  segment  by  the  seal- 
ing effect  of  a  special  washer,  and  this  provides  an  air  cushion  which 
makes  for  easier  riding  than  would  be  possible  with  a  solid  tire.  In 
event  of  damage  to  one  segment  it  may  be  removed  without  difficulty 
and  a  new  one  substituted. 

A  combination  cushion  tire  composed  of  a  heavy  solid-rubber 
tread  and  an  inner  tube  inflated  with  air  to  form  a  cushion  is  shown 
at  Fig.  319,  B.  It  is  claimed  for  this  construction  that  the  resiliency 
is  not x  greatly  diminished  and  that  the  tire  is  absolutely  puncture 
proof.  The  tire  consists  of  two  main  parts,  the  solid-rubber  outer 


The  Modern  Gasoline  Automobile  537 

tread  being  of  rubber  composition  and  mounted  on  a  base  of  fabric 
and  rubber,  and  the  air  tube,  which  is  inflated  and  which  provides 
the  resilient  effect.  Both  members  are  firmly  clamped  between  cir- 
cumferential steel  flange  side  rings.  The  inner  tube  rests  upon  an 
ordinary  steel  rim  or  bonding  member  attached  to  the  felloe,  which 
is  made  wider  than  the  usual  construction  and  of  channel  form.  The 
steel  flanges  are  extended  beyond  the  rim  and  are  turned  over  at 
their  outer  edge  in  such  a  way  that  they  form  grooves  to  hold  the 
beads  of  the  tire,  and  continue  to  the  base  of  rubber  tread,  where 
they  end  in  a  bead  and  leave  sufficient  space  between  them  for  the 
solid  tread  to  work  up  and  down.  One  of  the  flanges  is  permanently 
fastened  to  the  felloe,  while  the  other  is  removable  by  unscrewing 
the  clamping  nuts. 

It  is  claimed  that  as  the  flanges  enclose  the  air  tube  as  well  as 
the  weaker  portions  of  the  outer  member  which  are  subjected  to  the 
air  pressure,  a  very  strong  construction  is  obtained.  The  solid- 
rubber  tread  is  the  only  portion  that  comes  in  contact  with  the  road, 
and  provision  is  made  to  prevent  the  air  tubes  being  chafed  by  the 
sides  of  the  steel  rim  or  by  the  edges  of  the  outer  member.  When 
the  solid  tread  encounters  an  obstacle  in  the  road  it  is  pressed  inward 
against  the  air  tube  in  the  same  manner  as  the  conventional  form  of 
outer  shoe  is,  and  more  resiliency  is  obtained  than  with  the  rigid 
solid  form.  The  inner  tube  is  well  protected  from  puncture,  and  it 
is  also  claimed  that  blow-outs  are  almost  impossible,  because  to  reach 
the  inner  tube  it  would  be  necessary  to  pierce  either  the  heavy  solid 
tread  or  one  of  the  steel  side  flanges. 

Forms  of  Solid-Rubber  Tires. — On  heavy  commercial  vehicles  it  is 
not  practical  to  use  pneumatic  tires  because  these  would  have  to  be 
of  very  large  size  to  carry  the  loads  imposed  by  the  usual  heavy  truck 
chassis  and  loaded  body.  As  the  speeds  of  these  vehicles  are  not  very 
high,  solid-rubber  tires  may  be  employed  to  advantage.  These  are 
inolded  from  special  rubber  compositions  in  one  continuous  ring,  and 
they  are  usually  provided  with  some  form  of  metal  reenforcement  at 
the  bottom  which  insures  that  they  will  clamp  tightly  against  the 
rim  or  the  felloe  band.  Various  forms  of  quick-detachable  rims 
have  been  evolved  to  hold  these  members  in  place,  and  the  metal 
reinforcements  at  the  bottom  vary  from  simple  transverse  wires  to 


538 


The  Modern  Gasoline  Automobile 


continuous  bands  of  steel  molded  integral  at  the  base  of  the  rubber 
rings. 

A  number  of  solid  tires  and  methods  of  attachment  are  clearly 
shown  at  Fig.  320.  Single  tires  of  this  form  are  used  on  the  front 
wheels  of  practically  all  trucks,  though  the  rear  members  are  gen- 
erally supplied  with  dual  tires,  which  have  greater  carrying  capacity 
and  which  also  lessen  the  dangers  of  side  slip  on  wet  pavements. 


DIAMOND  WIRE 
MESH  BASE 


GOODYEAR  FLANGED  TYPE 


MOTZ  FLANGED  TYPE 


Fig.  320. — Outlining  Construction  and  Methods  of  Fastening  Solid-Rubber  Tires 

to  Wheels. 

When  twin  tires  are  used  it  is  desirable  that  they  be  installed  in  such 
a  way  that  they  can  be  readily  removed  from  the  wheel  for  replace- 
ment in  event  of  wear,  and  it  is  also  thought  necessary  to  provide 
means  of  attachment  of  such  nature  that  they  can  be  removed  inde- 
pendently, if  desired.  Various  dual  tire  forms  and  the  method  of 
holding  them  in  place  are  shown  at  Fig.  321.  The  construction  out- 
lined at  Fig.  322  shows  the  application  of  wedges  to  lock  the  solid- 
rubber  tires  firmly  to  the  wheel. 

When\solid-rubber  tires  were  first  applied  to  trucks  they  were  of 
such  form  that  special  machinery  was  needed  to  install  them,  and  the 


539 


540  The  Modern  Gasoline  Automobile 

work  could  only  be  done  at  depots  where  this  form  of  machinery 
formed  part  of  the  equipment.  When  accident  to  the  tire  or  natural 
wear  made  it  necessary  to  replace  the  worn  member  with  a  new  one 
the  wheel  had  to  be  removed  from  the  truck  and  sent  to  the  tire 
company's  station  to  be  fitted  up  with  tires.  This  meant  a  loss  of 


Fig.  322. — Hartford  Detachable  Twin  Solid- Tire  Construction. 

time  of  some  magnitude,  which  has  been  entirely  overcome  by  the 
new  demountable  construction.  Spare  tires  may  be  carried  in  stock 
and  may  be  used  to  replace  the  damaged  members  without  the  use  of 
special  applying  machinery  in  most  instances  and  without  necessitat- 
ing the  removal  of  the  wheel. 

Tools  and  Supplies  for  Pneumatic  Tire  Restoration. — It  has  been 
previously  stated  that  one  of  the  chief  disadvantages  of  pneumatic 
tires  has  been  their  liability  of  failure  by  puncturing  the  outer  casing 
and  penetrating  the  inner  tube  and  thus  providing  a  means  for  escape 
of  the  compressed  air  in  the  inner  tube.  The  life  of  a  pneumatic 
tire  is  decidedly  uncertain  and  will  depend  on  many  factors  outside 
of  those  of  purely  natural  wear.  There  have  been  cases  where  outer 
casings  have  given  satisfactory  service  for  seven  or  eight  thousand 
miles,  but  these  instances  have  been  the  exception  rather  than  the 
rule.  It  is  the  opinion  of  most  motorists  who  have  had  practical 
experience  that  if  an  ordinary  set  of  shoes  will  give  a  service  averag- 


The  Modern  Gasoline  Automobile 


541 


ing  two  thousand  miles  that  they  are  equal  to  the  demands  made  upon 
them  and  that  they  are  satisfactory.  It  may  be  stated  that  tires  will 
last  longer  on  light  cars  than  heavy  ones  and  the  service  obtained 
from  tires  fitted  to  vehicles  driven  at  low  and  moderate  speeds  will 


Air  Pump 


Outer  Casing 


Jack 


'ement 


Values 
Pressure  Gauge       Value  Toot 


Casing  Security  Bolts 


Fig.  323. — Spare  Parts  and  Necessary  Repair  Equipment  for  Automobiles  Using 

Pneumatic  Tires. 


542 


The  Modern  Gasoline  Automobile 


be  much  greater  than  that  obtained  from  tires  fitted  to  high-speed 
vehicles.  There  is  also  a  personal  element  which  must  be  taken  into 
consideration,  and  that  is  the  way  that  the  car  is  driven  and  the  care 
taken  of  the  shoes  and  inner  tubes. 


Fig.  324. — Forms  of  Tire  Irons  Used  in  Removing  and  Repairing  Clincher  Shoes. 

It  is  necessary,  therefore,  in  all  cars  using  pneumatic  tires  to 
carry  a  certain  amount  of  equipment  for  handling  and  repairing 
these  on  the  road.  A  typical  outfit  is  shown  at  Fig.  323,  this  con- 
sisting of  a  spare  outer  casing,  two  extra  inner  tubes  for  replacement 
purposes,  a  blow-out  sleeve,  a  number  of  patches,  and  an  acid-cure 
vulcanizing  outfit  for  applying  them.  Tire  irons  must  be  provided 
to  remove  the  casing  from  the  rim ;  the  jack  is  used  to  raise  the  wheel 
of  the  vehicle  on  which  the  defective  tire  is  installed  from  the  ground 
and  make  it  possible  to  remove  the  tire  completely  from  the  wheel. 
The  air  pump  is  needed  to  inflate  the  repaired  tube  or  the  new  mem- 
ber inserted  to  take  its  place.  The  talcum  powder  is  sprinkled  be- 
tween the  casing  and  the  tube  to  prevent  chafing  or  heating,  while 
the  spare  valves  and  valve  tool  wilLbe  found  useful  in  event  of  dam- 
age to  that  important  component  of  the  inner  tube.  As  it  is  desirable 
to  inflate  the  tires  to  a  certain  definite  pressure,  a  small  gauge  which 
will  show  the  amount  of  compression  in  the  tire  is  useful. 

The  outfit  shown  may  be  supplemented  by  other  forms  of  vulcan- 
izing sets  and  by  special  tire  irons  to  make  for  easier  removal  of  the 


The  Modern  Gasoline  Automobile 


543 


outer  casing.  Tire  irons  vary  in  design,  and  most  makers  of  tires 
provide  levers  for  manipulating  the  casings,  which  differ  to  some 
extent.  A  set  of  tire  irons  such  as  would  be  needed  with  a  clincher- 
tire  equipment  could  be  selected  from  the  forms  shown  at  Fig.  324. 
That  shown  at  A  is  utilized  to  loosen  the  clincher  bead  from  under 
the  rim  should  it  become  rusted  in  place.  After  the  shoe  has  been 
loosened  from  the  rim  flange  one  of  the  levers  of  the  form  shown  at 
B,  C,  or  D  would  be  inserted  under  the  bead  in  order  to  lift  it  over 
the  rim.  Two  or  more  of  these  levers  are  provided,  and  the  length 
and  form  will  vary  with  the  preference  of  the  motorist.  It  will  be 
remembered  that  the  longer  levers  are  more  easily  operated  than  the 
short  ones,  and  that  the  length  of  the  .lever  provided  will  depend 
entirely  upon  the  size  of  the  tire  to  be  removed. 


Fig.  325. — Small  Repair  Kit  Containing  Necessary  Tools  and  Supplies  for  Emer- 
gency Repairs. 

Motorists,  as  a  rule,  should  carry  the  releasing  lever  shown  at  A, 
two  of  the  short  members  depicted  at  B,  and  one  longer  lever,  such 
as  the  upper  one  of  group  C,  or  the  forms  D  or  E.  The  latter  is  a 


544 


The  Modern  Gasoline  Automobile 


combination  form  which  may  be  used  as  a  jack  handle  as  well  as  a 
tire  iron,  and  when  it  is  supplied  it  is  not  necessary  to  carry  a  jack 
handle  in  the  equipment.  The  flattened  ends  are  generally  employed 
for  prying  the  bead  from  the  clincher  rim,  and  when  this  has  been 


Knife 


Clamp 


Fig.  326. — Tools  Found  Useful  when  Repairing  Inner  Tubes. 

done  and  sufficient  space  exists  between  the  bead  and  the  rim  to  insert 
the  curved  end  of  the  larger  levers,  considerable  leverage  is  obtained 
and  the  bead  may  be  lifted  over  the  clincher  rim  without  undue 


Vulcanizer 


Lamp 


Patching  Rubber 


Molds 


Fig.  327.— Portable  Vulcanizer  Outfit  for  Filling  Cuts  in  Outer  Casings  or  Patch- 
ing Inner  Tubes. 


The  Modern  Gasoline  Automobile 


545 


exertion.  The  object  of  rounding  the  corners,  and  of  making  the 
working  portions  as  broad  as  possible,  is  to  reduce  the  liability  of 
pinching  the  inner  tube,  which  would  be  present  if  the  irons  had 
sharp  edges. 

The  tire-repair  material  is  sometimes  carried  in  a  special  case, 
as  shown  at  Fig.  325,  this  consisting  of  all  parts  necessary  to  make 
temporary  repairs  to  be  considered  in  proper  sequence.  This  outfit 
is  sometimes  supplemented  by  the  special  tools  shown  at  Fig.  326. 
The  knife  is  used  to  cut  the  rubber,  trim  patches,  'etc.  The  stitcher 
and  roller  are  useful  in  rolling  the  patch  after  it  has  been  cemented 


Brushes 


Emery  Cloth 


Acid 


Fig.  328. — Acid-Cure  Vulcanizing  Outfit. 

i    to  the  tire  to  insure  adhesion  of  the  patch  with  the  tube,  while  the 

.wooden  clamps  are  useful  in  binding  the  patch  firmly   against  the 

damaged   portion  of  the  tube  while   the  cement   is  drying.      Some 

I  motorists   carry   small   vulcanizers   in   order   to   effect   more   perma- 

j  nent  repairs  than  would  be  possible  with  the  simple  .patching  proc- 

|   esses    in   which   the    adhesive    powers    of   cement    are   utilized.      A 

i  simple  steam  vulcanizer  and  molds   for  use  in  connection  with  it 

!  are    shown   at    Fig.    327,    and   an   acid-cure    vulcanizing   set   which 

j  does  not  make  use  of  any  form  of  heating  apparatus  is  shown  at 

i  Fig.  328. 


546 


The  Modern  Gasoline  Automobile 


Tire-Manipulation  Hints. — In  removing  or  replacing  outer  casings 
considerable  care  must  be  exercised  not  to  injure  the  shoe  or  pinch 
the  inner  tube.  The  first  step  is  to  jack  up  the  wheel  from  which 
the  defective  tire  is  to  be  removed,  this  relieving  the  wheel  of  the 
car  weight.  The  valve  inside  is  then  unscrewed  in  order  to  allow  any 
air  that  may  remain  in  the  tube  to  escape,  and  then  the  lock  nuts 
on  the  valve  stem  and  security  bolts  are  removed  so  that  these 
members  may  be  lifted  to  release  the  clincher  beads  from  the  rim 
channels.  If  the  tire  is  stiff  or  has  not  been  removed  for  some 


Adjustable 
Hinged  Portion 


Flat  End 


Fig.  329. — Special  Appliance  for  Loosening  Clincher  Shoes  from  Rim  of  Wheel. 

time,  a  special  iron,  such  as  depicted  at  Fig.  329,  is  utilized  in 
the  manner  shown,  and  the  beads  are  pushed  clear  of  the  clincher 
rim.  When  the  casing  has  been  loosened  on  one  side,  a  flat  tool, 
such  as  shown1  at  Fig.  324,  B,  is  inserted  under  the  loose  bead  to 
act  as  a  pry  or  lever  to  work  the  edge  of  the  casing  gradually  over 
the  rim. 

Very  long  levers  are  necessary  to  handle  heavy,  stiff  tires,  and 
new  casings  are  particularly  hard  to  remove.  The  shorter  irons  iiiny 
be  employed  on  the  smaller  casings  and  on  shoes  which  have  been  used 


The  Modern  Gasoline  Automobile  547 

for  some  time  and  which  are  more  pliable  than  the  new  ones.  Two 
of  the  levers  are  generally  used  together,  one  being  kept  under  the 
loosened  edge  of  the  bead,  while  the  other  is  used  to  force  the  bead 
over  the  edge  of  the  rim.  When  the  outside  edge  of  the  bead  has 
been  forced  over  the  rim  at  all  points  the  inner  tube  is  lifted  from 
the  rim  and  is  pulled  out  of  the  shoe.  The  start  at  removing  is 
made  at  the  point  diametrically  opposite  the  valve  stem.  When  this 
portion  has  been  pulled  clear  of  the  rim  and  out  of  the  casing  it  is 
not  difficult  to  pull  the  rest  of  the  tube  out  and  finally  lift  the  valve 
stem  out  of  the  hole  through  which  it  passes  in  the  wheel  felloe,  and 
take  the  inner  tube  entirely  off  the  wheel. 

If  the  casing  demands  attention,  or  if  a  new  case  is  to  be  used, 
the  inside  bead  is  worked  over  the  channel  of  the  clincher  rim  in 
just  the  same  manner  as  was  done  with  the  outside  bead,  and  after 
a  start  has  been  made  and  a  portion  of  the  inside  bead  forced  over 
the  rim  there  will  be  no  difficulty  in  slipping  the  entire  shoe  from 
the  wheel.  Applying  a  tire  is  just  the  reverse  to  removing  one. 
The  first  operation  is  to  place  the  inner  bead  of  the  tire  in  position  in 
the  center  of  the  rim  by  forcing  it  over  the  outside  flange.  This  is 
done  gradually,  and  in  order  to  force  the  remaining  portion  of  the 
shoe  it  may  be  necessary  to  use  long  levels  when  the  greater  part  of 
the  casing  has  been  applied.  The  next  step  is  to  work  the  shoe 
gradually  toward  the  inner  channel  of  the  rim,  then  to  insert  the 
security  bolts  in  the  holes  made  to  receive  them. 

The  inner  tube  is  replaced  after  it  has  been  partially  inflated  by 
putting  the  valve  stem  in  first  and  then  inserting  the  rest  of  the 
tube,  being  careful  not  to  pinch  it  under  the  heads  of  the  lugs  or 
security  bolts.  After  the  inner  tube  has  been  put  in  place  the  outer 
bead  of  the  tire  is  worked  over  the  edge  of  the  rim,  the  portion 
adjacent  to  the  valve  stem  being  inserted  first.  When  working  the 
remainder  of  the  bead  over  the  rim  channel  much  care  must  be  exer- 
cised to  insure  that  the  inner  tube  will  not  be  pinched  by  the  sharp 
edges  of  the  tire  levers.  The  object  of  partially  inflating  the  inner 
tube  is  to  distend  it  so  there  are  no  loose  or  flabby  portions  that  are 
liable  to  catch  under  the  tire  bead  when  this  is  being  forced  in  place 
over  the  wheel  rim. 

The  mechanically  fastened  tires  are  much  easier  to  remove  than 


548 


The  Modem  Gasoline  Automobile 


clincher  shoes,  because  after  the  retaining  rims  are  taken  off  the 
wheels  the  outer  casings  can  usually  be  pulled  right  off  the  flat 
rim.  The  tools  and  the  manner  of  using  them  employed  in  taking 
off  Fisk  bolted-on  tires  are  shown  at'  Fig.  330.  The  clamp  is  employed 
when  replacing  the  shoe  and  it  serves  to  hold  the  retaining  ring  and 


B 


Fig.  330.— Tools  for  Removing  Fisk  "  Bolted  On  "  Casings  and  Method  of  Using 

Them. 

the  bottom  of  the  shoe  closed  in  such  a  way  that  the  nuts  on  the 
through  bolts  may  be  easily  tightened  up  by  using  a  socket  wrench 
depicted  at  A.  This  wrench  has  a  T  handle  with  a  hook  end,  and 
this  hook  is  sometimes  of  value  in  prying  off  a  retaining  ring  that 
has  become  rusted  in  place.  The  method  of  handling  these  tools 
and  this  type  of  tire  are  so  clearly  shown  that  further  description 
seems  unnecessary. 

Tire-removing  tools  are  made  in  many  forms,  and  more  have 
been  devised  for  use  with  clincher  type  of  casings  than  the  other 
forms  because  the  beads  on  these  casings  sometimes  become  so  firmly 
imbedded  in  the  rim  channels  that  it  is  extremely  difficult  to  remove 
them,  ^specially  if  the  shoe  has  been  on  the  rim  for  some  time.  An- 
other form  of  removing  tool  possessing  a  certain  amount  of  adjusta- 


The  Modern  Gasoline  Automobile 


549 


bility  which  makes  it  adaptable  for  use  in  connection  with  varying 
sizes  of  clincher  casings,  and  the  method  of  use,  is  shown  at  Fig.  331. 
In  tliis  form  the  main  or  handle  portion  has  a  piece  extending  from 
it  that  carries  a  rubber  roll  designed  to  pull  against  the  spoke.  The 
part  that  bears  against  the  shoe  is  a  separate  piece,  provided  with  a 
number  of  hooks  to  make  it  possible  to  alter  its  position  as  desired. 
For  use  with  a  small  tube  the  uppermost  notch  is  used,  and  as  the 
shoes  become  larger  the  notched  piece  is  pulled  farther  up  in  the  slot 
in  which  it  slides  on  the  head  of  the  Y-shaped  handle.  Tools  of 
this  nature  are  extremely  useful  and  should  form  part  of  the  equip- 
men  of  every  motorist  who  uses  clincher  tires. 


Fig.  331.— Adjustable  Iron  for  Loosening  Clincher  Casings  That  Have  Stuck  to 

Rims. 

Rules  for  Tire  Selection  and  Inflation. — The  tires  used  on  motor 
cars  are  generally  selected  by  considering  the  amount  of  load  sus- 
tained by  the  wheels  of  the  cars,  but  considerable  difference  of  opin- 
ion seems  to  obtain  regarding  the  way  the  weights  should  be  esti- 
mated. Tire  manufacturers  believe  that  the  entire  weight  of  the 
vehicle  with  all  possible  equipment  and  passengers  must  be  con- 


550  The  Modern  Gasoline  Automobile 

sidered,  but  there  have  been  cases  where  a  car  has  been  supplied  with 
tires  that  were  inadequate  because  only  the  weight  of  the  car  was 
considered  in  making  the  selection  and  the  added  load  of  passengers 
and  equipment  was  disregarded.  It  is  believed  desirable  to  provide 
rear  tires  that  will  be  twenty-five  per  cent  larger  than  those  needed 
merely  to  support  the  weight  of  the  rear  end  of  the  vehicle,  because 
in  the  majority  of  cases  these  members  are  called  upon  to  sustain 
stresses  incidental  to  traction  as  well  as  the  strains  produced  by  the 
vehicle  weight. 

It  is  customary  to  use  one  size  tire  on  the  four  wheels,  the 
thought  being  that  the  shoes  from  the  front  wheels,  which  are  not 
subjected  to  the  severe  service  that  those  on  the  rear  are  called  upon 
to  endure,  can  be  placed  on  the  rear  wheels  when  those  casings  be- 
come weakened  by  use,  and  their  place  taken  by  the  weakened  rear 
shoe,  which  may  have  sufficient  capacity  to  do  the  work  expected  of 
front-wheel  tires.  The  following  table  gives  the  proportion  between 
vehicle  weights  and  tire  sizes  that  are  commonly  accepted  by  tire 
manufacturers.  These  figures  are  based  on  the  maximum  permissible 
weight  of  a  car  without  passengers,  but  as  they  do  not  consider  the 
factor  of  possibilities  of  overload,  and  if  a  motorist  is  having  tire 

PROPORTIONS  BETWEEN  AXLE  LOADS  AND  TIRE  SIZES  ADOPTED 

BY  AMERICAN  TIRE  MAKERS 

/ 

2^-inch  tires,  all  diameters 225  pounds  per  wheel 

3      inch  tires,  all  diameters 350       "         "       " 

3^  x  28-inch  tires 400       " 

3Y2  x  30-inch  tires 450       " 

3y2  x  32-inch  tires 555       "         "       " 

3  Y2  x  34-inch  tires 600       " 

3^  x  36-inch  tires 600       "         "       " 

4  x  30-inch  tires 550       " 

4      x  32-inch  tires 650  "  "  " 

4      x  34-inch  tires 700  "  "  " 

4      x  36-inch  tires 750  " 

4H  x  32-inch  tires 700  "  "  " 

4^  x  34-inch  tires .  .  : 800  "  "  " 

43/6  x  36-inch  tires .  . 900  " 

For  weights  in  excess  of  1,000  pounds  per  wheel,  5-inch  tires  and  over  are 
recommended.  Weights  given  apply  to  car  without  passengers. 


The  Modern  Gasoline  Automobile  551 

troubles,  it  would  be  well  to  provide  tires  that  are  oversize  and  of 
more  than  sufficient  capacity.  Such  members  are  not  only  more 
enduring  than  shoes  which  are  barely  up  to  the  requirements,  but 
they  are  not  liable  to  blow  out  or  deteriorate  as  fast  as  overloaded  tires. 

Next  to  the  selection  of  proper  size  tires  the  important  con- 
sideration is  that  these  be  kept  properly  inflated.  If  a  tire  is  not 
properly  filled  with  air  it  will  flatten  out,  and  the  tendency  will  be 
to  separate  the  layers  of  fabric  and  rubber  of  which  the  shoe  is  com- 
posed, because  of  the  alteration  of  the  almost  round  or  tubular  section 
that  the  tire  is  supposed  to  be  when  in  use.  If  a  tire  is  properly 
inflated  the  walls  will  be  braced  from  inside  by  the  pressure  of  the 
compressed  air  in  the  inner  tube,  and  the  flattening  effect  will  have 
no  perceptible  effect  in  producing  disintegration  of  the  fabric  and 
rubber  plies  of  the  casing.  The  figures  given  in  tables  which  follow 
are  those  recommended  by  leading  tire  manufacturers  as  being  most 
suitable  for  the  various  sizes  of  tires  listed. 

These  usually  take  into  account  the  increase  in  temperature  and 
resulting  pressure  of  the  air  created  by  the  friction  between  the  tires 
and  the  roads  caused  by  prolonged  running.  A  French  authority 
has  made  a  series  of  tests  to  determine  what  the  increase  of  pressure 
would  be  on  tires  from  three  to  four  and  a  half  inches  in  diameter 
under  usual  touring-car  service  conditions.  These  results  are  pre- 
sented in  tabular  form  and  should  prove  very  interesting.  The  in- 
crease with  larger  tires  is  greater  in  proportion  because  the  walls  of 
the  casings  are  heavier  and  stiffer  and  greater  internal  strains  are 
produced  in  the  fabric  by  the  distortion  of  the  shoe  at  the  points  of 
bending. 

AIR    PRESSURES    FOR    INFLATING    PNEUMATIC    TIRES    RECOM- 
MENDED BY  LEADING  MAKERS 

Diameter  of  Tire,  Maximum  Weight  on  Air  Pressure  in  Tire, 

Inches  Wheel,  Ibs.  Ibs.  per  Square  Inch 

2%  225  50 

3  350  60 
3^  600  70 

4  750  80 
4^  1,000  90 

5  1,000  90 


552  The  Modern  Gasoline  Automobile 

INCREASE  IN  AIR  PRESSURES  CAUSED  BY  DRIVING 


INITIAL  PRESSURE 
IN  TIRE,  COLD 

WORKING  PRESSURE 
IN  TIRE,  WARM 

INCREASE   RESULTING 
FROM  WORK 

Lbs.  ptr  Sq.  In. 

Lbs.  per  Sq.  In. 

Lbs.  per  Sq.  In. 

71.116 

88.183 

17.067 

85.339 

105.750 

20.411 

99.562 

123.546 

23.984 

113.785 

141  .  920 

28.135 

128.008 

158.588 

30.580 

142.232 

176.368 

34.136 

The  conventional  method  of  inflating  tires  by  using  a  foot  pump 
does  not  always  insure  that  the  tire  will  receive  adequate  inflation, 
and  when  a  pump  is  employed  it  is  imperative  that  some  form  of 
gauge  be  provided  that  will  register  the  amount  of  pressure  inside 
of  the  tire  in  order  that  it  will  reach  the  figure  recommended  by 
the  tire  makers.  Different  methods  of  tire  inflation  have  been  de- 
vised which  eliminate  the  necessity  of  using  manually  operated  pumps. 
Obviously  a  simple  expedient  would  be  to  provide  a  small  power- 
driven  pump  that  could  be  actuated  by  any  convenient  mechanical  con- 
nection with  the  engine.  Another  method  is  to  use  an  air  bottle, 
which  is  a  steel  container  in  which  air  is  stored  under  great  pressure. 
The  air  is  compressed  to  such  a  point  that  a  tank  less  than  two  feet 
long  and  six  inches  in  diameter  will  furnish  sufficient  air  to  in- 
flate seven  or  eight  tires  of  average  size,  or  twelve  to  fourteen 
small  ones.  The  tanks  may  be  exchanged  at  small  expense  when 
exhausted  for  new  containers  holding  a  fresh  supply  of  air.  In 
some  tanks  gases  of  various  kinds  under  high  pressure  are  used 
and  the  motorist  may  obtain  these  on  the  same  basis  as  air  bottles 
are  supplied. 

All  devices  of  this  character  are  fitted  with  gauges,  to  indicate  the 
amount  of  pressure  in  the  tire,  and  to  prevent  overinflation.  If  a 
tire  is  not  properly  inflated  the  shoe  will  be  liable  to  various  kinds 
of  road  damage  and  will  be  easily  punctured,  while  if  the  pressure  is 
too  high  the  shoe  is  liable  to  "  blow-out "  at  any  weak  point  in  the 
structure.  A  tire-pressure  gauge  is  a  very  necessary  article  of  equip- 
ment in  any  car  and  its  proper  use  when  blowing  up  tires  will  insure 


The  Modern  Gasoline  Automobile 


553 


the  best  possible  results  if  the   schedule  recommended   by  the   tire 
manufacturers  is  adhered  to. 

Tire  Repair  and  Maintenance. — The  common  causes  of  tire  failure 
that  the  motorist  is  apt  to  encounter  are  shown  at  Fig.  332.     The 


Worn  Tread 


Stone  Bruise 


Sand  Blister 


Leaky  Valve 


Rim  Cut 


Blow-out 


^ — Chafed  Side 


Fig.  332.— Sectional  View  of  Pneumatic  Tire  Showing  Some  Conditions  Which 

Cause  Failure. 


554  The  Modern  Gasoline  Automobile 

most  common  is  natural  wear  of  the  tread  portion  of  the  tire.  The 
rubber  compound  in  contact  with  the  road  surface  wears  away  in  time, 
and  the  fabric  layers  which  constitute  the  breaker  strips  are  exposed. 
The  shoe  is  weakened  and  any  sharp  object  in  the  road  is  apt  to 
penetrate  the  weakened  case  and  puncture  the  inner  tube.  If  a  num- 
ber of  the  layers  of  fabric  comprising  the  body  of  the  shoe  are  cut 
this  constitutes  a  weak  place  in  the  casing  and  a  blow-out  will  result 
because  the  few  layers  of  fabric  remaining  do  not  have  sufficient 
strength  to  resist  the  air  pressure. 

A  stone  bruise  is  caused  by  the  removal  of  a  portion  of  the  rubber 
tread  by  a  sharp  stone,  piece  of  glass,  etc.,  and  is  much  more  serious 
than  a  puncture  because  it  removes  some  of  the  tire,  whereas  in  ordi- 
nary cases  of  puncture  a  sharp  object  merely  penetrates  the  casing. 
A  sand  blister  is  produced  by  sand  or  grit  from  the  road  working 
into  a  space  in  the  tire  between  the  tread  and  the  fabric  body  through 
some  neglected  incision  or  bruise.  The  side  of  the  tread  is  often 
chafed  by  running  the  tires  against  curb  stones  or  by  driving  in  car 
tracks.  Rim  cutting  is  generally  caused  by  insufficient  inflation 
which  permits  the  rim  to  cut  into  the  tire  and  thus  tends  to  sever  the 
bead  from  the  side  of  the  shoe. 

The  chief  inner  tube  trouble  is  penetration  of  the  wall  by  some 
sharp  object,  or  the  folding  over  of  part  of  the  tube  walls  when  the 
tire  was  applied.  The  parts  of  the  check  valve  sometimes  give 
trouble  and  the  valve  leaks.  In  cases  of  valve  trouble  it  is  usually 
cheaper  to  replace  the  valve  inside  than  it  is  to  attempt  to  fix  it. 
Some  of  the  causes  of  valve  leakage  are  hardening  of  the  rubber 
washer,  bent  stem,  which  prevents  the  valve  from  seating  properly  or 
a  particle  of  dust  or  other  foreign  matter  which  would  act  to  keep 
the  valve  from  closing  the  air  passage  positively. 

The  most  serious  condition  that  a  motorist  will  meet  with  is  a 
"  blow-out "  and  usually  only  temporary  repairs  can  be  made  on  the 
road.  The  common  methods  of  restoring  a  defective  outer  casing  are 
depicted  at  Fig.  333.  In  this  an  inner  sleeve,  which  is  composed  of 
a  number  of  plies  of  fabric,  is  placed  between  the  inner  tube  and  the 
broken  portion  of  the  outer  casing  to  prevent  pinching  of  the  inner 
tube  by  the  jagged  edges  of  the  cut,  and  to  strengthen  the  casing  from 
the  outside  an  outer  shoe  or  gaiter  made  of  leather  is  laced  around 


The  Modern  Gasoline  Automobile  555 

the  shoe.  The  object  of  using  both  inside  and  outside  reenforcing 
members  in  combination  is  to  not  only  strengthen  the  weak  outer 
casing  but  by  providing  an  outer  shoe  dirt  is  kept  from  working  into 
the  tire. 

Punctured  inner  tubes  may  be  temporarily  repaired  by  using 
a  cemented  surface  patch.  The  first  step  necessary  is  to  clean  the 
surface  of  the  tube  very  thoroughly  with  gasoline  and  then  to  rough 
up  the  surface  of  both  patch  and  portion  of  the  tube  surrounding  the 


reah  in  Casing 

uter  Shoe 


Outer  Casing 


Inner  Sleeue  with  Hooks 


Fig.  333. — Temporary  Casing  Repairs  Possible  When  Small  Blow-Out  or  Large 
Puncture  Occurs  on  the  Road. 

holes  with  a  wire  scratch  brush  or  with  sandpaper.  After  the  sur- 
faces are  properly  cleaned  and  roughened  the  patch  and  the  tube  are 
coated  with  suitable  patching  cement  which  is  alk>wed  to  become 
thoroughly  dry  before  the  second  coat  is  applied.  The  second  coat 
is  allowed  to  become  "  tacky/7  which  expresses  a  condition  where  the 
cement  is  almost  dry  and  yet  still  possesses  a  certain  degree  of  ad- 
hesiveness. The  patch  is  applied  to  the  cemented  portion  of  the  tube 
and  the  whole  is  clamped  firmly  together  to  secure  positive  adhesion 


556  The  Modern  Gasoline  Automobile 

while  the  cementing  medium  is  drying.  Patches  should  always  be  of 
sufficient  size  to  cover  the  damaged  portion  and  at  the  same  time  have 
about  three  quarters  of  an  inch  or  more  of  the  patch  at  all  sides 
of  the  orifice. 

Very  satisfactory  repairs  to  both  inner  tubes  and  outer  casings  of 
a  permanent  nature  can  be  made  by  using  small  portable  vulcanizers 
which  may  be  heated  by  either  electricity  or  vapor.  When  these  are 
used  a  special  vulcanizing  cement  is  necessary  and  uncured  rubber 
stock  must  be  used  for  patching  or  filling  openings  caused  by  punc- 
tures or  blow-outs.  The  patch  of  raw  material  is  applied  to  the 
cemented  surface  of  the  tube  or  casing  and  the  vulcanizer  heated  to 
the  proper  temperature.  The  heat  of  the  vulcanizer  causes  the  rub- 
ber of  the  patch  to  unite  perfectly  with  the  old  material  and  forms 
an  intimate  bond. 

In  vulcanizing  the  most  important  precaution  is  to  maintain  a 
proper  temperature.  Too  great  a  degree  of  heat  will  burn  the  rub- 
ber, while  a  proper  cure  cannot  be  effected  if  the  temperature  is  too 
low.  The  temperatures  recommended  for  vulcanizing  vary  from  250 
to  375  degrees  F.  The  lower  degree  of  heat  is  used  in  working  ma- 
terial that  has  been  previously  cured,  while  the  higher  temperature 
is  recommended  for  new  rubber.  A  number  of  small  portable  vulcan- 
izers and  their  method  of  use  is  shown  at  Fig.  334.  In  the  view  at 
A  the  vulcanizer  is  heated  by  electric  current  and  is  provided  with 
two  faces,  one  flat,  designed  for  use  against  inner  tubes,  and  the  other 
curved  to  conform  to  the  curvature  of  outer  casings.  In  the  view  A 
the  vulcanizer  is  shown  with  the  flat  face  in  use,  while  at  B  it  is 
shown  clamped  to  an  outer  casing  with  the  curved  face  in  contact 
with  the  tread.  The  heat  is  obtained  by  passing  a  current  of  elec- 
tricity through  suitable  resistance  coils  imbedded  in  the  body  of  the 
device. 

Where  electriq  current  is  not  available  various  forms  of  flame- 
heated  vulcanizers  may  be  used.  In  that  form  depicted  at  C  the 
vulcanizer  body  is  filled  with  water,  which  is  converted  into  steam 
by  the  heat  of  a  flame  furnished  by  the  alcohol  lamp  that  forms  part 
of  the  device.  This  form  of  vulcanizer  is  provided  with  a  flat  face 
as  well  as* -a  curved  one  and  can  be  used  for  either  inner  tube  or  outer 
casing  restoration.  A  combination  vulcanizer  which  is  composed  of 


The  Modern  Gasoline  Automobile 


557 


a  large  hollow  cast-iron  body  filled  with  water  and  heated  with  a 
spirit  lamp  is  depicted  at  D.     In  this  the  curved  face  and  the  flat 


Flat  Face  in  Use 


Curved  Face  in  Use 

LWood  Handle 


Vulcanizer 


Clamp 


Curved  Face  in  Use-\    /////, 
meter     Flat  Face  in  Use 


Vulcanizer 


Lamp 


7!  Clamp 


Curved  Face  in  Use 


Fig.  334.— Methods  of  Using  Small  Electric  or  Vapor  Vulcanizers  on  Tube 
and  Casing  Work,  a  Very  Convenient  Method  of  Effecting  Permanent  Re- 
pairs. 


558 


The  Modern  Gasoline  Automobile 


face  may  be  used  simultaneously  and  an  inner  tube  patched  at  the 
same  time  that  the  outer  casing  is  being  treated.  As  very  complete 
instructions  are  furnished  with  these  small  vulcanizers,  any  motorist 
may  become  familiar  with  their  use  without  much  difficulty. 

In  describing  the  methods  of  removing  clincher  casings  special 
emphasis  was  laid  on  the  necessity  of  careful  manipulation  to  prevent 
pinching  of  the  inner  tube.  The  manner  in  which  this  somewhat 


Fig.  335. — How  Inner  Tubes  May  Be  Pinched  and  Ruptured  if  Outer  Casing  is 
Replaced  Carelessly  or  if  Tire  Lugs  Are  Not  Properly  Placed. 

delicate  member  may  be  ruptured  when  applying  or  removing  outer 
casings  may  be  easily  understood  by  reference  to  Fig.  335.  At  A  the 
inner  tube  is  pinched  by  a  poorly  fitting  bead  which  does  not  bed 
properly  into  the  channel  of  the  rim.  At  B  a  portion  of  the  inner 
tube  has  bxeen  caught  under  the  bead  of  the  shoe  when  this  was  applied 
because  the  tube  was  not  properly  inflated  before  it  was  inserted  into 


The  Modern  Gasoline  Automobile  559 

the  casing.     At  C  and  D  the  inner  tube  has  been  pinched  by  care- 
lessly placed  or  poorly  fitting  security  bolt. 

The  rules  to  secure  satisfactory  operation  from  pneumatic  tires 
may  be  easily  summed  up.  In  the  first  place  it  is  imperative  that 
the  tires  be  inflated  to  the  pressures  recommended  by  the  manufac- 
turers and  that  they  be  selected  with  a  certain  margin  of  safety  over 
the  actual  requirements.  The  tires  should  be  kept  clean  and  free 
from  oil  or  grease  because  the  oleaginous  substances  used  for  lubri- 
cation very  quickly  attack  rubber  compounds  and  cause  crumbling 
and  rapid  deterioration.  Oil  or  grease  should  be  wiped  off  as  soon  as 
noticed  and  the  tire  cleaned  by  the  application  of  gasoline.  Any 
small  cuts  or  openings  in  the  tire  that  may  permit  water  to  enter  or 
sand  to  work  between  the  fabric  and  the  tread  will  cause  trouble  in 
time.  One  should  be  careful  in  driving  not  to  apply  the  brakes  too 
suddenly  because  this  will  lock  the  wheels  and  wear  the  tire  very 
quickly.  Care  should  be  taken  not  to  drive  in  car  tracks,  and  when 
highways  do  not  have  the  proper  surface  they  should  be  negotiated 
very  carefully  to  avoid  cutting  the  casings. 


CHAPTER    XI 

Motor-Car  Equipment  and  Accessories — Air-  and  Gas-Operated  Engine  Starters 
— Electric  Starting  Systems — Gas-  and  Electric-Lighting  Appliances  and 
Their  Use — Wind-Shield  Forms — Shock  Absorbers — Speedometer  and  Mile- 
age Indicators — Tool  Equipment  for  Ordinary  Repairs — Miscellaneous 
Supplies  of  Value  to  the  Motorist — How  Supplies  are  Carried. 

COINCIDENT  with  the  development  of  the  motor  car  there  has 
been  produced  a  large  number  of  accessories,,  some  of  which  make  for 
greater  comfort  while  touring  and  others  that  have  material  influence 
on  the  safety  of  the  car  and  its  occupants.  Many  accessories  have 
been  devised  for  application  to  motor  cars  of  various  classes,  but 
many  of  these  are  not  necessary  and  have  but  little  real  merit.  In 
this  exposition  the  writer  will  confine  his  remarks  to  tried  and  proven 
auxiliaries  desirable  to  include  in  the  motor-car  equipment  and  which 
may  really  be  regarded  as  necessary  to  obtain  the  maximum  amount 
of  pleasure  and  profit  possible  from  motoring. 

Many  of  the  devices  listed  are  now  supplied  by  manufacturers  as 
regular  equipment  because  they  are  considered  as  much  a  part  of  the 
car  as  some  of  the  more  important  components  belonging  to  the 
mechanism  proper.  Other  devices  of  considerable  value  must  be 
furnished  by  the  motorist  himself  and  when  one  tries  to  make  selec- 
tions from  the  stock  of  the  average  supply  house  it  is  quite  difficult  to 
differentiate  between  the  valuable  and  necessary  accessories  and  those 
which  are  not  needed  unless  one  is  guided  largely  by  the  experience 
of  others. 

Self-Starters  for  Gasoline  Engines. — One  of  the  disadvantages  of 
the  gasoline  engine  which  has  been  often  advanced  by  those  favoring 
steam  or  electric  power  is  that  it  is  difficult  to  start  it  in  some  cases, 
and  various  means  were  devised  to  overcome  the  objection  advanced. 
The  early  gas  engines  fitted  with  poorly  designed  carburetors  and  in- 
adequate ignition  systems  were  often  difficult  to  set  in  motion,  but  as 
the  gasoline  engine  was  improved  and  the  multiple-cylinder  form 

560 


The  Modern  Gasoline  Automobile  561 

gained  in  favor,  those  used  during  the  past  few  years  have  been  easy 
to  start  by  some  form  of  starting  handle  or  crank  and  often  a  quarter 
turn  of  that  member  is  sufficient  to  set  the  engine  in  motion  if  it  was 
in  proper  adjustment  and  the  various  auxiliary  groups  were  function- 
ing properly.  At  the  present  time  the  improvements  made  in  the 
gasoline  automobile  have  been  more  in  the  nature  of  detailed  refine- 
ment and  those  engaged  in  producing  motor  cars  have  studied  more 
carefully  the  various  points  which  make  automobiles  more  convenient 
and  more  easily  operated.  The  requirements  of  the  present  day  can- 
not be  met  by  easy  starting  motors  because  this  feature  is  common  to 
all  automobiles  from  the  smallest  runabout  to  the  heaviest  touring 
car  or  truck. 

The  present  demand  is  for  engines  that  are  equipped  with  some 
form  of  mechanism  which  will  make  them  self-starting,  that  is,  so 
that  they  may  be  set  in  motion  by  merely  pressing  a  button  or  push- 
ing a  valve  from. the  seat  and  not  by  the  usual  form  of  hand  crank 
at  the  front  of  the  car.  The  starting  handle  has  always  been  a  dan- 
ger point  and  many  broken  arms  and  fractured  wrists  have  resulted 
from  a  premature  explosion  of  gas  in  the  cylinders  which  forced  the 
starting  handle  backward  and  against  the  arm  or  hand  of  the  person 
starting  the  engine.  Motor-car  control  lias  been  simplified  to  a  point 
where  many  women  are  running  cars,  but  the  average  motor  requires 
the  expenditure  of  more  strength  than  that  possessed  by  the  average 
woman  or  young  person  to  start  it.  When  a  separate  starting  device 
is  fitted  the  motor  may  be  started  as  easily  by  a  person  lacking  in 
strength  as  by  one  who  can  "  spin  "  the  engine  around  at  will. 

Self-starters  operate  on  two  principles.  First,  that  in  which  the 
crank  shaft  is  rotated  by  some  form  of  external  mechanism  which 
causes  the  pistons  to  draw  in  a  charge  of  gas  in  the  usual  manner  and 
which  is  merely  a  mechanical  substitute  for  hand  cranking.  Second, 
those  systems  in  which  a  charge  of  gas  is  supplied  the  cylinders  and 
ignited  independently  of  crank-shaft  rotation.  Mechanical  starters 
include  all  devices  which  rotate  the  shaft  to  produce  the  cycle  of  oper- 
ations necessary  to  secure  the  power  impulse  in  the  cylinders,  and 
motion  may  be  imparted  to  the  crank  shaft  in  two  ways :  by  the  use 
of  independent  mechanism,  or  by  making  a  motor  of  the  engine  itself. 

The  independent  motor  devices  may  be  spring,  air,  or  electrically 


562 


The  Modern  Gasoline  Automobile 


operated  mechanisms.  Spring  motors  have  not  attained  the  popular- 
ity that  air  or  electric  motors  have  because  they  weigh  considerable 
and  occupy  more  space  than  would  be  needed  by  the  other  types. 
Their  capacity  is  limited  because  the  energy  is  supplied  by  a  spring 


.  Special  Check  Values 


rank 


Acetylene  Tank 


Fig.  336. — Simple  Ignition  Starting  System  Using  Acetylene  Gas  and  Hand-Oper- 
ated  Distribution  Valve  on  Dash. 

or  springs  which  become  unwound  and  which  cannot  supply  any 
energy  when  they  are  uncoiled.  Spring  motors  are  usually  geared  to 
the  crank  shaft  and  thrown  out  of  gear  by  automatic  means  after  the 
engine  is  started  when  the  springs  have  been  wound  to  the  proper  de- 
gree of  tension.  Air  and  electric  motors  have  received  some  appli- 
cation, but  as  a  general  rule  it  is  the  simpler  ignition  starters  that  are 
the  vogue. 

Features  of  Ignition  Starters. — It  is  not  an  uncommon  thing  to 
start  a  four-  or  six-cylinder  motor  by  merely  turning  on  a  switch 
because  a  certain  amount  of  unexploded  gas  may  remain  in  one  of  the 
cylinders  and  this  may  be  compressed  to  a  point  where  it  will  explode 
as  soon  as  an  electric  spark  takes  place  in  the  cylinder  to  fire  the  gas. 
It  is  natural,  then,  that  the  first  starting  systems  proposed  should 
incorporate  some  means  of  furnishing  a  charge  of  gas  to  the  engine 
and  then  exploding  it.  The  gas  supplied  may  be  either  carbureted 


The  Modern  Gasoline  Automobile 


563 


gasoline  or  acetylene  and  the  conditions  which  exist  are  similar  to 
those  present  when  the  engine  is  started  on  the  spark. 

A  simple  form  of  gas-starting  systems  is  outlined  at  Fig.  336. 
Special  check  valves  are  inserted  in  each  cylinder  head  of  the  four- 
cylinder  motor  and  are  supplied  with  gas  through  a  special  form  of 
hand-operated  rotary  distributor  valve  carried  on  the  dash..  The  gas 
is  supplied  from  an  acetylene  tank  and  one  or  two  turns  of  the  dis- 
tributor handle  serves  to  supply  gas  to  the  cylinder,  the  piston  of 
which  is  at  the  upper  center  and  in  the  proper  position  to  receive  the 
impact  of  the  exploded  gas.  Turning  on  the  switch,  provided  that 
the  car  is  a  form  using  battery  ignition  as  an  auxiliary  or  regular 
system,  will  suffice  to  produce  a  spark  in  the  cylinder  to  which  the 
gas  has  been  introduced  and  will  start  the  motor. 

•  Gasoline  is  sometimes  used  as  a  starting  medium  and  when  this 
is  employed  some  form  of  pump  is  used  to  force  an  explosive  vapor 
into  the  cylinder.  An  upward  movement  of  the  pump  handle  draws 
in  a  certain  amount  of  gasoline  from  the  tank  and  air  through  some 


Anchor 


Seat 


1-2  \\Da9h 

Center  Line  of  Handle, 
6°o  U    when  in  normal  position 


Anchor 


To  Carburetor 


Fig.  337. — Ignition  Starting  System  in  which  a  Hand-Operated  Pump  Forces 

Mixture  to  Cylinders. 

form  of  special  inlet  check,  and  when  the  pump  handle  is  depressed 
the  gasoline  mixture  is  pumped  into  the  proper  cylinder  through  a 
pipe  which  is  attached  to  some  form  of  distributor  or  selector  valve 
to  direct  the  gas  stream  to  the  proper  explosion  chamber.  A  system 
which  depends  upon  supplying  gas  is  shown  .at  Fig.  337.  In  this 


564 


The  Modern  Gasoline  Automobile 


the  hand  pump  is  placed  in  front  of  the  operator's  seat  in  such  a 
position  that  the  .handle  may  be  conveniently  reached  by  the  driver 
or  passenger.  A  couple  of  strokes  of  the,  pump  suffices  to  supply 
enough  explosive  mixture  to  start  the  engine  when  the  ignition  cir- 
cuit is  completed.  The  gasoline-starting  system  is  not  as  popular  as 
that  using  acetylene  gas  because  the  latter  gas  will  explode  easier 
and  the  operator  does  not  need  to  exercise  the  degree  of  judgment 
that  is  needed  when  supplying  a  gasoline  vapor. 

Compressed-Air  Starting  Systems. — Two  forms  of  air-starting  sys- 
tems are  in  general  use,  one  in  which  the  crank  shaft  is  turned  by 
means  of  an  air  motor,  the  other  class  where  compressed  air  is  ad- 
mitted to  the  cylinders  proper  and  the  motor  turned  over  because  of 


Dash  Value  Control 

Air  Gauge 

Connection  for  filling  Tires 
Pump  engaging  foot  Treadle 


Safety  Valve — J 


fil 

*M 

Air  Supply  Tank 

ySelf  Starter 


Fig.  338. — Never-Miss  Starting  System  with  Special  Air  Motor  for  Mechanical 

Cranking. 

the  air  pressure  acting  on  the  pistons.  A  system  known  as  the  "  Never- 
Miss  "  is  shown  at  Fig.  338.  In  this  a  small  double-cylinder  air 
pump  is  driven  from  the  engine  by  means  of  suitable  gearing  and 
supplies  air  to  a  substantial  container  located  at  some  convenient 
point  on  the  chassis.  The  air  is  piped  from  the  container  to  a  dash- 
control  valve  and  from  this  member  to  a  peculiar  form  of  air  motor 
mounted  near  the  crank  shaft.  The  air  motor  consists  of  a  piston  to 


The  Modern  Gasoline  Automobile 


565 


which  a  rack  is  fastened  which  engages  a  gear  mounted  on  the  crank 
shaft  provided  with  some  form  of  ratchet  clutch  to  permit  it  to  revolve 
only  in  one  direction,  and  then  only  when  the  gear  is  turning  faster 
than  the  engine  crank  shaft. 

The  method  of  operation  is  extremely  simple,  the  dash-control 
valve  admitting  air  from  the  supply  tank  to  the  top  of  the  pump 
cylinder.  When  in  the  position  shown  in  cut  the  air  pressure  will 
force  the  piston  and  rack  down  and  set  the  engine  in  motion.  The 


Special  Cylinder  Control  Values 


Fig.  339. — Janney-Steinmetz  Compressed-Air  Starting  System. 

valve  is  a  special  form  and  the  piping  is  arranged  in  such  a  manner 
that  a  current  of  air  may  be  sent  against  the  bottom  of  the  piston 
when  it  has  reached  the  end  of  its  stroke  to  return  it  to  the  top  of 
the  pump  cylinder.  When  the  piston  reaches  the  bottom  of  its  stroke, 
the  air  is  automatically  discharged  through  a  series  of  exhaust  open- 
ings in  the  cylinder  wall. 

An  air  gauge  is  placed  on  the  dash  so  that  the  pressure  of  air  in 
the  supply  tank  may  be  ascertained  at  a  glance.  If  the  pressure  is 
lower  than  it  should  be  a  foot  treadle  is  depressed  and  the  air  pump 
put  into  action  by  meshing  the  driven  gear  on  the  pump  crank  shaft 
with  the  driving  member  that  supplies  power  from  the  engine.  When 
the  air  pressure  is  sufficiently  high  the  treadle  is  released  and  the 


566 


The  Modern  Gasoline  Automobile 


pump  ceases  to  supply  air.  A  safety  valve  is  installed  on  the  tank  to 
relieve  any  excess  pressure  which  might  accumulate  if  the  pump  is 
kept  in  action  longer  than  needed. 

Another  form  of  air-starting  system  in  which  air -is  supplied  di- 
rectly to  the  cylinders  of  the  motor  through  a  special  distributor  ar- 
rangement is  shown  at  Fig.  339.  The  small  air  pump  is  driven  by 
gear  connection  from  the  engine  in  the  usual  manner,  and  supplies 
air  to  a  pressure  tank.  The  distributor  is  driven  in  much  the  same 
manner  and  at  the  same  speed  as  an  ignition  distributor  used  on  a 
magneto,  and  the  arrangement  of  piping  is  such  that  the  air  is 


Fig.  340.— Parts  of  Air-Starting  Group  Supplied  on  Chalmers  Cars.  A — Pressure- 
Supply  Valve.  B — Compressed  Gas  Tank.  C— Dash  Starting  Button.  D 
— Mechanical  Distributor.  E — Cylinder  Check  Valves.  F — Gas  Shut-Off. 
G — Pressure  Gauge  on  Dash.  H  and  I — Air  Connection  for  Tire  Inflation. 

supplied  to  the  cylinders  in  the  regular  firing  order.  When  the 
foot  valve  is  depressed  air  is  admitted  to  the  cylinders  and  the  engine 
is  kept  in  motion  by  air  pressure  until  it  has  inspired  a  charge  of  gas 
which  becomes  ignited  and  starts  the  motor  on  its  cycle  of  operation. 
The  starter  used  on  the  Chalmers  car  and  fitted  to  the  car  as 
an  integral  part  of  the  power  plant  is  shown  at  Fig.  340.  In  this  a 
check  valve  in  the  head  of  Number  1  cylinder  stores  air  under 
pressure  in  a  tank  carried  in  the  body  of  the  car.  A  dash  valve  re- 
leases air  from  the  tank  when  it  is  desired  to  start  the  motor  and  this 
is  carried  to  a  distributor  operating  upon  the  same  principles  as  the 


The  Modern  Gasoline  Automobile  567 

usual  form  of  ignition  commutator.  The  compressed  air  is  sent  to 
the  cylinders  which  are  ready  for  firing  and  in  this  way  the  motor  is ' 
operated  and  the  crank  shaft  turned  by  the  air  pressure  until  sufficient 
gas  has  been  drawn  in  from  the  carburetor  by  the  downwardly  moving 
piston  to  make  ignition  effective.  One  of  the  disadvantages  of  the 
air-starting  system  shown  at  Figs.  339  and  340  is  that  these  are 
not  effective  if  the  motor  should  stop  on  dead  center,  i.  e.,  when  the 
piston  in  the  working  cylinder  is  exactly  at  the  top  of  its  stroke.  This 
condition  is  one  that  seldom  obtains  in  a  gasoline  engine  because  the 
natural  tendency  is  for  the  pistons  to  balance  themselves  in. such  a 
way  that  they  are  nearer  the  middle  of  their  stroke  than  the  dead 
center  position.  Should  a  motor  stop  on  dead  center  it  may  be 
easily  turned  over  a  small  amount  by  the  hand  crank  and  then  the 
self-starting  device  immediately  becomes  operative.  One  of  the  ad- 
vantages of  these  systems  is  that  they  furnish  air  for  tire  inflation 
as  well  as  for  motor-starting  purposes.  When  used  on  a  six-cylinder 
engine  the  objection  advanced  that  the  motor  is  liable  to  stop  on 
dead  center  is  not  to  be  considered  as  with  a  four-cylinder  motor. 

Electric  Starting  Systems. — Starters  utilizing  electric  motors  to 
turn  over  the  engine  have  been  recently  developed,  and  when  properly 
made  and  maintained  in  an  efficient  condition  they  answer  all  the 
requirements  of  an  ideal  starting  device.  The  capacity  is  very  high, 
as  the  motor  may  draw  current  from  a  storage  battery  and  keep  the 
engine  turning  over  for  half  an  hour  on  a  charge.  The  objection 
against  their  use  is  that  it  requires  considerable  complicated  and  costly 
apparatus  which  is  difficult  to  understand  and  which  requires  the 
services  of  an  expert  electrician  to  repair  should  it  get  out  of  order. 

A  typical  electric  starter,  such  as  used  on  the  Cadillac  car,  is  out- 
lined at  Fig.  341.  The  apparatus  necessary  consists  of  some  source 
of  electric-current  supply,  means  for  storing  electricity,  and  some 
method  of  applying  the  power  to  rotate  the  engine.  In  the  Cadillac 
system  the  electric  current  is  generated  by  a  combined  motor  genera- 
tor permanently  geared  to  the  engine.  When  the  motor  is  running 
it  turns  the  armature  and  the  motor  generator  is  acting  as  a  dynamo, 
only  supplying  current  to  a  storage  battery.  On  account  of  the  vary- 
ing speeds  of  the  generator,  which  are  due  to  the  fluctuation  in  engine 
speed,  some  form  of  automatic  switch  which  will  disconnect  the  gener- 


568 


The  Modern  Gasoline  Automobile 


ator  from  the  battery  at  such  times  that  the  motor  speed  is  not 
sufficiently  high  to  generate  a  current  stronger  than  that  delivered  by 
the  battery  is  needed.  These  automatic  switches  are  the  only  delicate 
part  of  the  entire  apparatus,  and  while  they  require  very  delicate 
adjustment  they  seem  to  perform  very  satisfactorily  in  practice. 


Magneto 
Distributor 


Distributor 
Coil 


Motor  Gen 


Fig.  341. — Motor  Generator  Employed  in  Starting  Cadillac  Motor  also  Furnishes 
Current  for  Ignition  and  Lighting. 

When  it  is  desired  to  start  the  engine  an  electrical  connection  is 
established  between  the  storage  battery  and  the  motor-generator  unit, 
and  this  acts  as  a  motor  and  turns  the  engine  over  by  suitable  gearing 
which  engages  the  gear  teeth  cut  into  the  engine  fly  wheel.  On  the 
Cadillac  car  the  motor  generator  furnishes  current  for  ignition  and 
lighting  as  well  as  for  starting  the  motor,  and  the  fact  that  the  current 
can  be  used  for  this  work  as  well  as  starting  justifies  to  a  certain 
extent  the  rather  complicated  mechanism  which  forms  a  complete 
starting,  lighting,  and  ignition  system. 


The  Modern  Gasoline  Automobile  569 

Summing  up  the  advantages  of  these  various  self-starters,  it  would 
seem  that  in  most  cases  very  satisfactory  results  could  be  obtained 
from  the  forms  in  which  acetylene  gas  is  introduced  to  the  cylinders 
and  then  ignited  by  turning  on  the  switch.  These  ignition  starters 
have  a  disadvantage,  however,  that  they  cannot  be  used  where  ignition 
is  by  magneto  without  battery  auxiliaries.  Starters  which  rotate  the 
crank  shaft  have  the  advantage  that  they  can  start  a  motor  even  if  it 
is  equipped  with  a  magneto  because  they  will  turn  an  engine  over 
faster  than  is  possible  by  hand  power,  and  the  result  is  that  a  spark 
of  adequate  strength  will  be  generated  to  ignite  the  gas  even  if 
batteries  and  coil  are  not  provided. 

The  disadvantage  of  air-starting  systems  is  that  the  air  chills  the 
cylinders  and  makes  starting  somewhat  difficult  in  cold  weather  or 
when  conditions  are  such  that  the  gasoline  mixture  is  not  properly 
proportioned.  If  considered  merely  from  the  point  of  view  of  results 
obtained,  it  would  seem  that  the  electric  starter  with  its  capacity  for 
a  large  number  of  motor  starts  per  charge  of  batteries  would  be  the 
most  suitable  form.  As  previously  stated,  however,  its  mechanical 
complication  is  a  strong  enough  disadvantage  that  many  consider 
it  of  sufficient  moment  to  outweigh  the  advantages  of  the  system. 

Motor-Car-Lighting  Systems. — When  tjie  automobile  was  first  in- 
vented it  was  a  comparatively  slow-speed  conveyance,  and  ordinary 
oil  lamps  such  as  used  on  carriages  or  bicycles  for  illuminating  the 
roadway  at  night  proved  adequate  for  the  newer  form  of  conveyance. 
As  cars  have  become  improved  it  was  found  necessary  to  provide 
stronger  radiants  than  kerosene  lamps  to  illuminate  the  roadway 
because  of  the  greater  speed  capabilities  of  the  improved  automobile. 

In  order  to  provide  higher  illuminating  powers  than  would  be 
present  by  using  kerosene  alone,  the  kerosene  lamps  were  supple- 
mented by  search  lights  supplied  with  burners  designed  to  burn  acety- 
lene gas.  Two  methods  of  furnishing  acetylene  gas  to  the  burners 
are  in  use,  one  being  to  use  some  form  of  generator  which  makes 
the  gas  as  it  is  needed,  the  other  is  to  take  the  gas  required  from  some 
container  where  it  has  been  stored  under  pressure. 

The  usual  form  of  generator  employed  in  connection  with  gas 
lamps  is  shown  at  Fig.  342,  A.  The  acetylene  gas  is  generated  by 
combining  water  with  calcium  carbide,  the  latter  being  a  mixture  of 


570  The  Modern  Gasoline  Automobile 

coke  and  lime  which  has  been  fused  together  in  an  electric  furnace. 
Pure  calcium  carbide  will  produce  about  5.5  cubic  feet  of  gas.  per 
pound  of  carbide  decomposed,  'but  the  commercial  product  seldom 
yields  more  than  4.5  cubic  feet.  Acetylene  is  a  very  brilliant  illumi- 
nating gas  and  gives  a  white  light  of  about  240  c.  p.  if  burned  at 
the  rate  of  five  cubic  feet  an  hour.  The  strength  of  illumination  can 
be  better  judged  by  comparing  it  with  that  produced  by  burning 
five  cubic  feet  of  good  coal  gas  in  the  same  period  of  time  which 
will  only  result  in  16  c.  p. 

A  special  form  of  burner  is  used  in  the  automobile  headlight, 
which  mixes  a  certain  amount  of  air  with  the  gas  and  the  brilliant 
white  light  produced  is  intensified  and  projected  by  means  of  a  lens 
mirror  placed  at  the  back  part  of  the  lamp.  This  lens  serves  to  collect 
and  concentrate  the  rays  of  light  from  the  flame  into  a  beam  com- 
posed of  parallel  rays  which  have  great  illuminating  power,  and  which 
will  light  up  the  road  for  hundreds  of  feet  ahead  of  the  car  and  per- 
mit higher  speeds  with  safety  than  would  be  possible  with  the  feeble 
glimmer  of  oil  lamps. 

The  generator  employed  and  its  mode  of  action  may  be  easily 
understood  by  referring  to  Fig.  342,  A.  It  consists  of  a  water  tank 
and  separate  compartments  for  carbide  and  gas  and  a  filtering  cham- 
ber. Water  is  dropped  on  the  carbide  and  as  soon  as  the  two  come 
in  contact  the  chemical  begins  to  decompose  and  acetylene  gas  is 
liberated  while  lime  dust  collects  in  the  bottom  of  the  generator  as  a 
residue.  The  gas  collects  in  a  reservoir  and  forces  its  way  through  a 
filter  chamber  filled  with  wool  or  similar  material  which  filters  the 
gas.  The  gas  is  also  cooled  before  it  reaches  the  lamps  because  the 
gas  outlet  pipe  and  filter  is  surrounded  with  water. 

When  the  shut-off  valve  is  opened  it  permits  the  water  which  has 
collected  in  the  intermediate  chamber  to  drop  into  the  carbide  basket 
through  a  perforated  tube.  If  the  pressure  in  the  intermediate  com- 
partment is  normal  atmospheric  pressure,  the  water  will  drop  freely 
onto  the  carbide  until  considerable  gas  is  liberated.  Just  as  soon 
as  the  gas  generated .  has  an  appreciable  pressure  it  flows  into  the 
intermediate  chamber  and  prevents  more  water  reaching  the  carbide 
until  the  gas  pressure  is  lower.  The  generator  will  continue  to  supply 
gas  as  long  as  the  supply  of  water  and  carbide  lasts. 


Fig.  342. — Gas  Generators  and  Lamps  Used  in  Connection  with  Acetylene  Head- 
light Installation. 
571 


572  The  Modern  Gasoline  Automobile 

The  forms  of  lamps  used  are  shown  at  Fig.  342,  B  and  C,  and  the 
method  of  installing  a  generator  and  lamp  outfit  is  clearly  outlined 
at  D.  The  headlights  are  usually  placed  at  the  front  end  of  the 
frame  where  they  are  carried  by  suitable  brackets  or  yokes,  and  con- 
nection with  the  generator  is  made  by  lines  of  copper  and  rubber 
tubing  which  convey  the  gas  from  the  generator  to  the  burner.  A 
trap  is  sometimes  interposed  between  the  generator  and  the  burners 
to  arrest  any  foreign  matter  or  moisture  that  may  have  passed  through 
the  filtering  material  in  the  gas  outlet  pipe. 

The  method  of  installing  a  compressed  acetylene  storage  tank 
sometimes  used  to  supply  the  gas  instead  of  the  generator  shown 
at  E  has  advantages  in  that  the  tank  may  be  easily  reached  when  it 
is  desired  to  replace  it,  and  at  the  same  time  it  is  out  of  sight  and  not 
liable  to  become  damaged.  When  the  construction  of  the  car  does  not 
permit  the  use  of  a  separate  locker  for  the  gas  tank  this  member  is 
often  carried  on  one  of  the  running  boards  of  the  car. 

'When  acetylene  lamps  are  used  they  are  usually  supplemented  by 
a  set  of  oil  lamps  which  are  provided  at  the  sides  of  the  dash  and 
as  a  rear  signal;  while  the  kerosene  lamps  do  not  give  much  light 
they  are  dependable  in  every  way  because  they  are  very  easy  to  under- 
stand and  require  no  care  except  an  occasional  trimming  of  the  wicks 
and  filling  with  kerosene.  If  the  acetylene  lamps  did  not  function 
properly  the  kerosene  flames  would  provide  sufficient  illumination  so 
that  the  roadway  immediately  in  front  of  the  car  would  be  lit  up 
enough  to  detect  obstacles,  and  at  the  same  time  the  lamps  would 
act  as  a  warning  signal  to  other  users  of  the  highways.  Kerosene 
lamps  are  also  useful  for  city  driving  where  the  intense  glare  of  the 
acetylene  lamps  would  be  annoying.  The  usual  motor-car  lighting 
system  consists  of  two  headlights,  burning  acetylene  gas,  two  dash 
lamps,  and  one  tail  light  burning  kerosene. 

If  a  gas  generator  is  kept  clean  and  properly  filled  with  carbide 
and  water  there  will  be  no  trouble  in  obtaining  adequate  supplies  of 
gas.  While  burners  sometimes  clog  up  it  is  a  very  easy  matter  to 
clean  out  the  openings  with  a  fine  piece  of  wire  or  to  supply  a  new 
burner  if  the  defective -one  cannot  be  repaired. 

Electric-Lighting  Systems. — During  the  past  year  many  manu- 
facturers have  employed  electric  lamps  to  advantage  on  automobiles, 


The  Modern  Gasoline  Automobile 


573 


and  while  these  were  formerly  fitted  only  to  the  high-grade  cars  the 
development  made  in  providing  suitable  current  producers  and  lamps 
having  strong  filaments  has  made  possible  the  application  of  electric 
lighting  to  all  classes  of  cars.  The  usual  method  of  current  supply  is 
by  storage  battery,  somewhat  similar  in  principle  to  those  used  for 
supplying  ignition  current  but  which  are  more  substantially  con- 
structed and  have  plates  of  greater  capacity  than  those  usually  pro- 


Expansion  Chamber  to  take 
care  of  Changes  in  Volume 
of  Solution  during  Charge 
and  Discharge. ' 


Plastic  Sealing 
Compound. "~ 


Hardwood  Case. 


Battery  Terminal 
covered  with  Rub- 
ber to  prevent 
Creeping  of  Acid. 


Para  Rubber 
Jar. 


Plates  and 

Elements. 


.  Plate  or  Element 

Supports  of  Hard 

Rubber. 


Fig.  343. — Special  Storage  Battery  Employed  to  Furnish  Lighting  Current. 

vided  in  ignition  cells.  The  construction  of  a  typical  lighting  battery 
is  shown  at  Fig.  343,  this  form  having  been -designed  especially  for 
this  class  of  work. 

Mechanical  generators  of  electricit}''  are  also  used  in  various 
forms,  and  a  number  of  small  dynamos  have  been  used  successfully 
in  connection  with  a  storage-battery  system.  When  a  dynamo  is  pro- 
vided it  usually  supplies  its  current  directly  to  a  storage  battery,  and 
the  electricity  for  lighting  is  taken  from  the  storage  battery  rather 
than  the  dynamo.  The  reason  for  this  is  that  any  fluctuation  of 
engine  speed  makes  the  current  production  vary  in  value.  If  the 


574 


Tlie  Modern  Gasoline  Automobile 


engine  was  running  slow  and  the  lamps  were  attached  directly  to 
the  generator  there  would  not  be  sufficient  illumination.  At  the 
other  hand,  if  motor  speeds  were  high  and  the  generator  was  driven 
faster,  enough  current  might  be  produced  to  burn  out  the  lamps. 
When  the  current  from  the  dynamo  is  directed  to  a  storage  battery 
that  member  serves  as  an  equalizer  and  will  maintain  a  constant  dis- 
charge to  the  circuit  in  which  the  lamps  are  wired.  It  will  absorb 


Fig.  344. — Side  and  Tail  Lamps  Using  Electric  Bulbs  for  Illumination.  A — 
Kerosene  Side  Lamp  with  Tungsten  Lamp  in  Corner.  B — Pillar  Lamp  for 
Limousine  Bodies  Uses  Electric  Lamp  Exclusively.  C — Small  Electric  Tail 
Lamp. 

excess  electricity  generated  at  high-motor  speeds  and  will  supply 
that  energy  to  .the  lamps  at  such  time  that  the  generator  would  be 
inadequate  to  supply  the  proper  amount  of  current. 

Various  forms  of  lamps  utilizing  electric  bulbs  are  shown  at  Figs. 
344,  345,  and  346.  Those  at  A,  Fig.  345,  are  side  lamps  that  have 
been  designed  especially  for  use  with  electric  current,  while  those 
depicte'd  at  B  are  combination  forms  in  which  the  electric  light  bulb 
has  been  inserted  in  an  oil  lamp  of  conventional  pattern  in  such  a 


The  Modern  Gasoline  Automobile 


575 


way  that  it  will  not  interfere  with  the  normal  operation  of  the  kero- 
sene burner  should  it  be  desired  to  use  the  kerosene  flame.  This 
feature  is  one  that  provides  an  important  advantage  in  that  a  failure 


B 


Oil  Container 


Oil  Fount 


Fig.  345. — A — Side  Lamps  Designed  to  Use  Only  Electric  Bulbs.     B— Methods 
of  Combining  Kerosene  Burner  and  Tungsten  Bulb  in  Side  Lamps. 


576 


The  Modern  Gasoline  Automobile 


of  the  electric  lamps  or  source  of  current  would  not  seriously  incon- 
venience the  motorist,  as  he  could  use  the  kerosene  burner  and  secure 
adequate  illumination  to  enable  him  to  operate  the  car  without 
danger.  The  combination  shown  at  Fig.  346  shows  the  adaptability 


Red  Lens 


Fig.  346. — Gray  &  Davis  Combined  Electric  Tail  Lamp  and  License  Plate  Holder, 
a  Device  of  Marked  Utility. 

and  simplicity  of  the  electric  light  to  good  advantage.  In  this  the 
electric  lamp  is  mounted  in  connection  with  a  license  number  in  such 
a  way  that  a  stream  of  white  light  is  thrown  on  the  number  to  il- 
luminate it,  whereas  a  red  lens  shows  a  danger  signal  to  the  rear. 

The  most  important  component  of  the  modern  electric  lighting 
system,  and  one  that  has  made  electric  lighting  practical,  is  the  incan- 
descent lamp.  This  produces  light  because  a  filament  of  conducting 
material  becomes  heated  by  the  passage  of  electric  current  and  gives 
off  rays  when  it  is  in  an  incandescent  condition.  The  electric  bulbs 
used  in  automobile  lighting  systems  have  tungsten  filaments  instead 
of  the  carbon  members  formerly  widely  employed  in  lamps  used  for 
house  lighting.  The  tungsten  filament  gives  a  more  intense  and 
concentrated  light  than  the  other  forms,  and  its  current  consumption 
is  much  lower.  The  filament  is  stronger  and  more  enduring  as  it 
is  not  liable  to  be  broken  by  vibration  incidental  to  motor  car  use. 
An  ordinary  carbon  filament  consumes  about  3.5  watts  per  candle 
powei*,-  while  the  tungsten  loop  uses  but  1.25  watts  to  provide  the 
same  degree  of  illumination.  The  economy  of  the  tungsten  filament 


The  Modern  Gasoline  Automobile 


577 


is  of  special  importance  if  the  current  used  for  lighting  is  derived 
from  a  chemical  source,  and  even  if  a  mechanical  generator  is  used 
this  can  be  made  lighter  and  more  compact  and  require  less  power 
to  drive  it  than  if  ordinary  carbon  filament  lamps  of  equivalent 
candle  power  were  used. 

The  types  of  lamps  and  bases  used  are  shown  at  Fig.  347.  The 
bulb  shown  at  A  has  a  cluster-loop  filament  and  an  Edison  screw 
base.  The  lamp  is  screwed  into  a  suitable  threaded  socket  and  the 
circuit  is  completed  when  the  stud  on  the  lamp  bottom  makes  contact 
with  a  suitable  contact  spring  in  the  socket.  The  objection  advanced 
against  the  Edison  screw  base  is  that  this  may  be  lopsened  by  vibra- 
tion, and  as  soon  as  the  lamp  becomes  loose  and  the  button  at  the 
bottom  leaves  a  contact  spring  the  circuit  will  be  interrupted  and 
the  light  go  out.  The  continued  vibration  may  cause  the  lamp  to 
work  out  of  the  socket  and  become  broken. 

Many  motorists  favor  the  Edi-Swan  method  of  bulb  retention. 
In  this  the  lamp  base  is  plain  and  is  provided  with  a  couple  of  small 
locking  pins.  A  special  slotted  socket  is  used  and  when  the  lamp  is 


Edison  Cluster 

Screw  Socket        Loop. 


Edi-Swan  Base.          Bayonet  Joint  Socket 


Fig.  347. — Incandescent  Bulbs  and  Sockets  Used  in  Motor-Car  Lamps. 

put  in  place  it  depresses  a  strong  spring  that  makes  contact  and  which 
also  locks  the  lamp  firmly  in  place  when  it  is  given  a  quarter  turn, 
so  the  pins  fit  into  small  depressions  at  the  side  of  the  main  slot. 
This  form  of  lamp  cannot  jar  loose  and  it  is  easily  inserted  or  re- 
moved from  its  socket.  The  object  of  using  a  short  and  thick  fila- 


578 


The  Modern  Gasoline  Automobile 


ment  of  the  cluster-loop  type  is  to  provide  for  secure  anchorage  of 
the  leading  in  wires,  and  at  the  same  time  to  provide  a  more  intense 
and  concentrated  light,  which  is  better  adapted  for  use  with  the  forms 
of  reflectors  where  the  lamp  must  be  at  the  correct  focal  point  to 
secure  proper  projection  of  the  beam  of  light. 

When  an  electric-lighting  system  is  provided  the  current  can  be 
adapted  to  other  uses  besides  merely  providing  illumination  of  the 
roadway.  Small  fixtures  used  for  illuminating  the  speedometer,,  oil 
gauge  or  clock  may  be  easily  brought  into  use  by  merely  pressing  a 
push  button  located  at  some  convenient  point.  The  interior  of 


Wire 


Reflector 


Fig.  348.— Convenient  Electric  Fixtures  That  May.  Be  Included  in  Equipment  of 
Cars  Using  Electric  Lighting  Systems. 

limousine  bodies  may  be  brightly  illuminated,  and  other  conveniences 
in  the  form  of  trouble  lamps  and  cigar  lighters  may  be  used  to  ad- 
vantage. Some  of  the  special  forms  of  lamps  are  shown  at  Fig.  348. 
That  at  A  is  a  small  dash  fitting  designed  to  throw  the  light  from 
the  lamp  directly  against  the  face  of  a  clock  or  speedometer.  A 
useful  "  trouble  lamp "  which  combines  a  cigar  lighter  as  well  is 


The  Modern  Gasoline  Automobile 


579 


shown  at  B.  The  bulb  is  mounted  in  a  special  reflector  attached  to  a 
suitable  handle  which  is  connected  to  the  source  of  current  by  a  long, 
flexible  wire  cable  which  permits  the  lamp  to  be  used  at  all  points 


Bulb  Adjusting  Screw 


Lamp  Shell 


Focusing  Rod 


Focusing  Lever 


Wires 


Glass 


Fig.  349.— Sectional  View  of  Gray  &  Davis  Electric  Headlight  Showing  Method 
of  Focusing  Bulb  by  Accessible  Adjusting  Screw. 

of  the  car.     The  form  shown  at  C  is  a  modification  of  the  dash  type 
depicted  at  A  and  is  used  as  a  side  bracket  for  interior  illumination 
of  closed  bodies.     The  search  light  illustrated  at  D  is  a  modified 
form  of  that  shown  at  B  and  does  not  combine  a  cigar  lighter. 
An  electric  headlight  of  very  good  design  is  shown  at  Fig.  349. 


580 


The  Modern  Gasoline  Automobile 


The  lamp  is  mounted  in  a  movable  base  that  may  be  adjusted  so 
the  bulb  will  always  be  in  the  proper  relation  to  the  parabolic  re- 
flector to  throw  an  intense  beam  of  light.  As  will  be  evident  the 
construction  of  such  a  lamp  is  simple  and  makes  possible  smooth 
forms,  which  are  much  neater  appearing  than  gas  lamps  if  only  the 
electric  filament  is  used  for  illumination. 

Many  automobilists  are  inclined  to  be  suspicious  of  innovations, 
and  because  of  their  familiarity  with  kerosene  oil  and  gas  lamps  they 


Fig.  350.— Combination  Headlight  Fitted  with  Both  Gas  Burner  and  Electric 
Bulb.  A— Position  of  Bulb  with  Gas  Flame  in  Use.  B— Bulb  Furnishing 
Light. 

desire  to  retain  these  and  use  the  electric  bulb  as  well.  This  is  easily 
done  in  the  case  of  side  lights  by  putting  in  a  bulb  at  some  point 
where  it  will  not  interfere  with  the  regular  burner.  Gas  burning 
headlights  may  be  converted  to  use  electric  current  when  desired 
by  simple  adapters  as  depicted  at  Fig.  350.  These  are  clamp  members 
attached  to  the  burners.  A  lamp  socket  is  mounted  in  such  a  man- 
ner that  it  may  be  swung  out  of  the  way  as  shown  at  A,  when  it  is 
desired  to  use  the  gas  flame  or  moved  back  so  that  it  occupies  about 
the  same  position  relative  to  the  lens  mirror  as  does  the  gas  flame 


I 


§ 
<s 

bfi 


a 

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581 


582  The  Modern  Gasoline  Automobile 

when  electric  light  is  desired.  The  position  of  the  bulb  at  times  it 
is  desired  to  use  electricity  instead  of  gas  is  shown  at  Fig.  350,  B. 

A  typical  simple  lighting  system  such  as  would  be  used  on  a 
light  runabout  or  car  employing  acetylene  gas  search  lights  is  de- 
picted at  Fig.  35'1.  In  this  case  the  side  lamps  are  provided  with 
two-  or  four-candle-power  bulbs,  while  a  two-candle-power  lamp  will 
be  found  of  adequate  capacity  for  the  tail  lights.  The  current  can 
be  supplied  either  by  a  multiple  series  dry  battery  of  at  least  twelve 
cells  or  a  six- volt,  sixty-ampere-hour  storage  battery.  With  this  sys- 
tem the  lamps  do  not  consume  any  more  current  than  would  be 
provided  by  the  normal  discharge  rate  of  an  ignition  battery  and  the 
same  type  of  current  producer  used  for  ignition  work  can  be  ap- 
^plied  to  small  electric-lighting  systems  without  trouble.  If  lamps  of 
higher  candle  power  are  used,  which  consume  more  current,  it  will 
be  necessary  to  use  a  special  lighting  battery  of  about  eighty  ampere- 
hour  capacity.  The  three  lamps  are  controlled  by  a  single  switch 
and  the  method  of  wiring  is  so  clearly  shown  that  it  can  be  easily 
followed  by  anyone  desiring  to  install  a  simple  electric-lighting 
system. 

A  more  comprehensive  lighting  system  such  as  would  be  used  on  a 
high-powered  touring  car  is  shown  at  Fig.  352.  In  this  the  head- 
lights are  provided  with  ,  twelve-  or  sixteen-candle-power  bulbs,  the 
side  lights  with  six-candle-power  bulbs,  the  tail  light  with  a  four- 
candle-power  lamp.  The  small  meter  light  which  is  wired  in  series 
with  the  tail  lamp  is  fitted  with  a  one-candle-power  filament.  The 
current  supply  is  by  a  dynamo  and  storage  battery  which  delivers  a 
current  of  about  twelve  volts  pressure.  An  automatic  switch  is  pro- 
vided  so  the  dynamo  will  supply  current  to  the  battery  only  when 
it  is  being  run  at  sufficient  speed  to  insure  the  delivery  of  a  proper 
amount  of  electric  current.  The  current  for  the  lamps  is  taken 
from  the  battery  which  is  kept  charged  by  the  dynamo.  A  three-unit 
switch  is  provided  with  buttons  controlling  three  circuits.  One  of 
these  is  the  headlight  group,  the  side  lamps  are  on  another  circuit, 
and  the  tail  lamp  and  meter  light  are  controlled  by  an  individual 
switch.  The  object  of  putting  the  meter  light  in  series  with  the 
tail  lamp  is  to  furnish  indication  to  the  operator  if  the  tail-light  bulb 
should  burn  out.  If  the  meter  light  is  out  the  tail  light  will  go  out 


583 


1 


584 


The  Modern  Gasoline  Automobile 


also,  and  vice  versa.  As  is  true  of  the  group  at  Fig.  351,  the  wiring 
diagram  may  be  easily  understood  and  will  be  useful  as  a  guide  for 
the  installation  of  a  complete  electric-lighting  equipment. 

Utility  of  Wind  Shields. — One  of  the  items  of  equipment  that  con- 
duces to  comfort  of  the  occupant  is  the  wind  shield.  In  winter 
this  member  serves  to  deflect  the  cold  wind  and  provide  a  transparent 
shelter  for  those  behind  it  while  in  summer  it  is  useful  in  screening 
the  eyes  when  driving  on  dusty  roads.  Wind  shields  are  made  in  many 


Celluloid 


Metal  Frame 

.Glass 


B 


Leather 


Fig.  353.— Conventional  Wind-Shield  Forms. 

forms,  though  the  usual  materials  employed  are  celluloid  and  leather 
or  wood,  metal,  and  glass  in  combination,  l^pical  wind-shield  forms 
are  shown  at  Fig.  353.  That  at  A  consists  of  a  metal  frame  covered 
with  leather  and  provided  with  transparent  celluloid  windows.  Side 
curtains  extend  from  the  frame  to  the  sides  of  the  seats  and  the 
passengers  are  completely  protected.  Another  form  of  celluloid  and 
leather  wind  shield  is  shown  at  B.  This  differs  from  the  form  previ- 
ously described  in  that  it  is  vertical,  whereas  that  shown  at  A  is  in- 


The  Modern  Gasoline  Automobile  585 

clined  at  an  angle  and  will  offer  less  air  resistance  than  the  forms 
which  are  at  right  angles  to  the  frame-side  member.  The  advantages 
of  using  celluloid  are  that  it  is  lighter  than  glass  and  that  it  is  not 
liable  to  become  broken.  The  disadvantage  to  its  use  is  that  it  will 
crack  very  easily  and  cannot  be  looked  through  as  easily  as  the  less 
opaque  glass. 

Glass  wind  shields  are  usually  composed  of  a  frame  of  brass  tubing 
in  which  large  panes  of  plate  glass  are  set.  The  frames  are  usually 
constructed  with  joints  so  the  top  portion  of  the  wind  shield  may  be 
swung  down  out  of  the  way  when  it  is  not  needed.  The  metal  frame 
which  carries  the  glass  is  set  on  a  wood  filler  piece  of  such  form  that 
it  will  fit  the  dash,  and  the  whole  assembly  is  braced  by  means  of  rods 
extending  from  the  lower  frame  to  the  front  or  sides  of  the  car,  as 
shown  at  Fig.  353,  C  and  D.  Wind  shields  are  an  indispensable  item 
of  equipment  and  no  automobile  can  be  considered  complete  without 
this  useful  means  of  protection. 

Function  of  Shock  Absorbers. — Even  when  the  springs  of  automo- 
biles have  been  very  carefully  selected  with  reference  to  the  loads  they 
are  to  sustain,  as  previously  stated,  it  is  difficult  to  make  provision  for 
the  many  variations  in  loads  and  speed  of  the  vehicle.  A  car  that 
will  be  very  easy  riding  on  good  roads  wiJU  be  uncomfortable  on  rough 
highways  because  the  light  springs  jounce  the  occupants  around  if 
the  car  is  operated  at  anything  except  slow  speed.  In  order  to  pro- 
vide smooth  riding  it  is  customary  to  select  springs  that  are  a 
compromise  and  that  will  not  be  too  hard  riding  on  good  road 
surfaces  and  yet  will  not  move  unduly  when  the  car  is  run  over 
rough  roads. 

Various  forms  of  shock  absorbers  have  been  devised  to  supplement 
the  action  of  the  vehicle  springs.  These  may  be  in  two  forms,  those 
designed  merely  to  receive  shocks  caused  by  sudden  spring  deflections 
and  other  appliances  devised  to  check  excessive  motion  of  the  springs 
by  providing  a  dampening  action.  The  simplest  form  of  shock  ab- 
sorber is  shown  at  Fig.  354,  A.  This  is  designed  for  use  with  springs 
which  are  too  flexible  and  which  may  settle  down  if  the  car  is  loaded 
to  its  capacity.  A  rubber  buffer  is  carried  by  a  clip  piece  extending 
under  the  spring  clips  to  hold  the  rubber  pad  in  place.  An  angle 
bracket  is  riveted  to  the  frame-side  member  if  the  spring  is  hung  out- 


586 


The  Modern  Gasoline  Automobile 


side  of  the  frame,  and  this  carries  a  bolt  which  engages  with  a  rubber 
bumper  to  stop  excessive  movement  of  either  frame  or  spring. 

An  auxiliary  spring  designed  to  work  in  conjunction  with  the 
main  supporting  members  is  shown  at  Fig.  354,  B.  This  is  a  heavy 
coil  spring  carried  inside  of  the  frame  member,  one  end  being  at- 
tached to  a  forging  bolted  to  the  frame  side  and  the  other  to  the 


Frame  Side 

\ 


Stop  Bolt 


C 


Fig.  354. — Methods  of  Promoting  Easy  Riding  of  Automobiles  Supplied  with 

Inadequate  Springs. 

axle.  Such  a  spring  will  not  interfere  with  small  spring  deflections, 
but  it  will  prevent  excessive  motion  of  the  frame  or  axle  either  on 
spring  depression  or  rebound.  When  springs  are  so  stiff  that  they 
will  not  yield  readily  to  the  minor  inequalities  of  the  road  surfaces 
it  is  customary  to  provide  some  form  of  auxiliary  spring  as  shown  at 
Fig.  354,  C.  A  spring  of  this  nature  replaces  the  usual  shackle  or  link, 
and  the  small  coil  springs  will  yield  readily  to  obstacles  that  would 
make  no  impression  on  the  stronger  leaf  spring. 

Shock  absorbers  that  act  by  producing  a  dampening  effect  to  check 
spring  movement  are  shown  at  Fig.  355.  The  simplest  of  these  com- 
prises a  pair  of  levers  hinged  together  at  one  extremity  and  attached 
to  the  frame  and  spring,  respectively.  The  form  shown  at  A  has  a 
friction  pad  between  the  two  portions  at  the  hinge  and  this  member 
provides  the  dampening  effect  desired.  The  form  shown  at  B  is 
somewhat  different  in  principle.  One  of  the  levers  is  cup  shape  while 
the  other  carries  a  cam.  A  number  of  steel  springs  are  inserted  in 
the  cup  and  excessive  movement  of  either  frame  or  axle  is  prevented 


The  Modern  Gasoline  Automobile 


587 


by  the  friction  effect  of  the  three-point  cam  on  the  three  compound 
leaf  springs  inside  of  the  cup. 

Many  other  forms  of  shock  absorbers  have  been  devised,  some 
consisting  of  cylinders  filled  with  oil  and  having  a  piston  to  act  as  a 
check  to  prevent  too  rapid  movement  of  a  plunger  rod  working  in  the 
cylinder.  One  member  would  be  secured  to  the  axle  and  the  other 
to  the  frame.  Many  makers  furnish  shock  absorbers  as  an  item  of 
regular  equipment,  and  if  a  car  which  is  not  equipped  with  these  mem- 
bers does  not  ride  as  comfortably  as  desired  the  spring  action  may 
always  be  improved  by  installing  some  form  of  shock  absorber  best 
adapted  to  meet  the  conditions.  Springs  that  are  too  flexible  should 
either  have  their  action  dampened  or  should  be  provided  with  some 
auxiliary  buffer.  Hard  riding  springs  can  be  improved  by  the  use 
of  auxiliary  cushion  springs  as  shown  at  Fig.  354,  C. 


Cup  filled 
'with  Grease 


Steel  Springs 
Anti-Friction  Fibre 

B 


Spring^ 


Fig.  355. — Efficient  Shock  Absorbers  That  Improve  Spring  Action  on  Rough 
Roads.  A — Truffault-Hartford  with  Friction  Pad.  B — Connecticut  Device 
Moves  Cam  Against  Spring  Resistance. 

Signals  and  Alarms. — The  laws  of  most  commonwealths  make  it 
imperative  for  the  motorist  to  equip  his  car  with  some  form  of  warn- 
ing signal  that  will  be  adequate  to  advise  other  users  of  the  highway 
of  the  car's  approach.  Many  forms  have  been  devised  ranging  from 
simple  reed  horns  operated  by  hand  pressure  on  a  small  rubber  bulb 
to  more  complex  alarms  in  which  an  electric  motor  serves  to  actuate 
a  diaphragm  and  produce  a  noise  that  can  be  heard  for  a  long  distance. 


588 


The  Modern  Gasoline  Automobile 


A  combined  hand-  and  electrically-operated  signal  is  shown  at  Fig. 
356,  A.  An  ordinary  form  of  bulb-operated  reed  horn  is  attached 
to  the  sound  intensifier  of  an  electrically  operated  signal.  The  object 


Fig.  366.— Forms  of  Motor-Car  Alarms  That  Give  Satisfactory  Service.  A — 
Combined  Klaxon  Signal  and  Bulb  Horn.  B  and  C — Exhaust  Whistles. 
D — Electrically  Operated  Signal. 

of  combining  the  two  alarms  in  one  is  to  provide  a  hand-operated 
alarm  for  ordinary  driving,  while  the  louder  electrical  signal  is  em- 
ployed when  the  sound  must  be  heard  for  a  considerable  distance. 

The  signals  shown  at  B  and  C  are  operated  by  the  exhaust  gases 
and  are  attached  to  the  end  of  the  exhaust  pipe.  They  are  operated 
by  depressing  a  small  foot  pedal  on  the  foot  board,  and  various 
sounds  may  be  produced  from  a  mellow  note  to  a  shrill  whistle  de- 
pending upon  engine  speeds.  The  alarm  shown  at  D  is  operated  by 
electrical  means  and  the  diaphragm  is  actuated  by  a  small  electric 
motor  which  will  run  from  the  storage  battery  usually  employed  for 
ignition  purposes.  The  advantage  of  the  electrically  operated  sig- 
nals that  makes  them  popular  is  apparent.  The  push  button  may 
be  attached  to  the  steering  wheel  convenient  to  the  driver's  hand  and 


The  Modern  Gasoline  Automobile 


589 


the  signal  may  be  obtained  by  a  simple  pressure  of  the  finger,  which 
is  sufficient  to  close  the  circuit  and  actuate  the  apparatus  which  pro- 
duces the  sound. 

Speed-Measuring  Devices. — When  one  considers  the  stringent  laws 
of  most  communities  regulating  the  speed  of  motor  vehicles  it  will  be 
evident  that  some  form  of  speed-indicating  device  is  necessary  to  show 
the  velocity  at  which  the  car  is  traveling  at  any  time.  Speedometers 
are  usually  combined  with  odometers  or  mileage  counters,  and  it  is 
not  uncommon  to  provide  a  clock  as  well.  A  speedometer  has  other 
uses  besides  merely  indicating  the  rate  of  travel.  It  forms  an  excel- 
lent indication  of  the  value  of  different  carburetor  adjustments  and  it 
enables  the  motorist  to  compile  definite  figures  regarding  fuel  and 
oil  consumption  or  tire  depreciation  for  a  given  period  of  time. 

Various  speedometer  forms  are  shown  at  Fig.  357.  That  at.  A  is 
a  simple  instrument  to  indicate  the  speed  and  distance.  The  type 
depicted  at  B  indicates  the  total  distance  traversed  and  the  number  of 


Electric, 
Lamp 


Fig.  357. — Speedometers  Useful  in  Indicating  Speed  and  Mileage. 

miles  covered  on  each  trip  as  well  as  the  speed.  It  is  provided  with 
a  small  electric  lamp  at  the  top  to  illuminate  the  dial  at  night.  The 
speedometer  shown  at  C  has  all  of  the  features  of  the  other  two 
instruments  with  the  added  one  of  having  a  clock  to  indicate  the 
time.  Speedometers  are  usually  placed  on  the  dashboard  of  the  car 


590 


The  Modern  Gasoline  Automobile 


and  are  driven  from  the  front  wheels  by  means  of  suitable  reduction 
gears  mounted  on  the  steering  knuckle  and  a  flexible  shaft. 

Speed  indicators  may  operate  on  different  principles,  some  de- 
pend on  magnetism,  or  the  flow  of  liquids,  others  utilize  centrifugal 
force  and  operate  just  the  same  as  the  fly-ball  governor  of  an  engine, 
An  instrument  which  depends  upon  the  principle  of  centrifugal 
force  to  "indicate  speed  is  shown  in  section  at  Fig.  358.  The  driving 


Cover  Glass 


Needle 


Mileage  Recorder 


Bevel  Gear, 


Governor  Weights 


Attachment  Lug 


Driving  Shaft 


Fig.  358.— Sectional  View  of  Speedometer  Which  Depends  on  Centrifugal  Force 
Stored  in  Governor  Weights  to  Actuate  Indicating  Needle. 

shaft  carries  a  pair  of  weights  which  are  thrown  out  as  the  speed 
increases.  These  weights  swing  a  pair  of  segments  meshing  with 
the  circular  rack  and  impart  an  up  and  down  reciprocating  motion 
to  this  member  as  they  revolve.  The  circular  rack  meshes  with  a 
small  spur  pinion  and  its  reciprocating  motion  is  converted  to  an 
oscillating  one  by  means  of  the  pinion.  A  pair  of  bevel  gears  trans- 


The  Modern  Gasoline  Automobile  591 

mit  the  motion  of  the  spur  pinion  to  the  speed-indicating  needle  at 
the  top  of  the  apparatus.  The  weights  and  their  position  are  so 
calculated  that  as  the  speed  increases  they  fly  out  from  center  and 
pull  down  the  circular  rack.  This,  in  turn,  moves  the  spur  pinion 
and  bevel  gears,  and  causes  the  needle  to  register  the  speed  corre- 
sponding to  the  position  of  the  governor  weights. 

A  small  train  of  gearing  similar  in  principle  to  that  used  in  a 
bicycle  cyclometer  is  carried  between  the  speedometer  case  and  the 
dial,  and  serves  as  a  distance-recording  gauge.  The  driving  shaft 
to  which  the  governor  weights  are  attached  is  driven  by  a  flexible 
shaft  connecting  to  one  of  the  front  wheels  •  in  the  conventional 
manner.  It  is  contended  that  speedometers  which  depend  on  centrif- 
ugal force  are  more  accurate  under  all  conditions  than  those  utiliz- 
ing either  magnetism  or  the  flow  of  liquids  to  indicate  the  speed. 
Those  who  favor  the  magnetic  principle  advance  the  contention  that 
instruments  of  this  character  are  more  sensitive  and  will  register 
low  speeds  more  accurately  than  instruments  depending  upon  centrif- 
ugal force.  All  of  the  many  forms  on  the  market  have  been  used 
with  success,  however,  and  any  speedometer  of  a  reputable  make  is 
certain  to  furnish  satisfactory  service.  Some  form  of  speed-indicat- 
ing device  should  be  installed  on  every  car,  and  their  obvious  utility 
can  be  easily  understood  when  one  remembers  that  the  amount  of  one 
fine  for  fast  driving  will  pay  for  a  very  efficient  speed-indicating 
and  mileage-recording  instrument. 

Tools  and  Miscellaneous  Equipment. — In  equipping  a  car  for  the 
season's  use  many  factors  must  be  considered,  as  the  character  of  the 
supplies  and  spare  parts  required  will  vary  with  the  type  and  make 
of  car,  while  the  tools  needed  for  repairing  the  mechanism  will  de- 
pend largely  upon  the  mechanical  ability  of  the  car  owner  or  the 
person  in  charge  of  the  automobile.  While  a  very  complete  outfit  of 
tools  and  spare  parts  would  be  the  best  insurance  against  trouble, 
it  should  be  remembered  that  the  weight  of  the  tool  outfit  should 
be  kept  to  as  low  a  point  as  possible.  As  a  general  rule  comparatively 
few  well  chosen  tools  that  would  be  apt  to  be  used  often  would  be 
superior  to  an  indiscriminately  selected  bulky  outfit  by  one  who  has 
no  knowledge  of  the  value  of  the  various  appliances  or  how  to  use 
them.  In  modern  motor  cars  it  is  easy  to  find  storage  room  for  a 


592  The  Modern  Gasoline  Automobile 

very  complete  assortment  of  tools  and  supplies,  and  while  some  of  these 
may  be  considered  unnecessary  there  may  be  a  time  when  it  will  be 
invaluable  especially  if  much  touring  is  contemplated. 

The  first  point  to  consider  is  selecting  the  common  tools  that  one 
would  be  apt  to  need  and  as  a  guide  a  very  complete  tool  roll  such  as 
sold  by  practically  all  automobile  supply  houses  at  a  moderate  price  is 
shown  at  Fig.  359.  The  choice  of  a  container  for  tools  and  supplies 
is  very  important  and  while  the  tool  roll  depicted,  which  is  made 
of  heavy  canvas  or  leather,  is  very  useful  it  has  the  disadvantage  of 
being  inconvenient  to  handle.  As  it  must  be  unrolled  every  time 
certain  of  the  tools  would  be  needed,  the  ground  is  usually  the  only 
available  place  for  its  extension  and  the  contents  and  casing  may 
become  very  dirty.  The  writer  prefers  to  use  a  tool  box  in  which 
a  number  of  trays  are  fitted.  These  are  divided  into  compartments, 
each  tool  having  a  distinct  space  and  to  insure  against  rattle  or 
injuring  the  tools  the  various  compartments  may  be  lined  with  felt 
or  heavy  cloth.  A  very  good  method  of  making  the  trays  is  to  have 
these  composed  of  or  filled  in  with  a  wooden  block,  which  is  recessed 
to  fit  the  tools  to  be  carried.  A  container  of  this  nature  is  superior 
to  others  as  the  tools  needed  most  often  can,  be  placed  in  the  upper- 
most tray,  making  them  accessible,  while  in  a  roll  the  tools  needed 
most  often  may  be  carried  in  the  center.  Some  motorists  throw  the 
tools  indiscriminately  into  a  box  and  the  result  is  that  many  of  the 
appliances  are  damaged  by  coming  in  contact  with  other  tools.  The 
cutting  edges  of  cold  chisels  and  wire  cutters  are  nicked,  the  teeth 
of  files  become  broken  or  filled  up  with  dirt,  and  screw  driver  points 
may  become  quickly  blunted,  and  their  utility  reduced.  At  the 
same  time  the  handles  and  polished  surfaces  of  the  other  tools  have 
become  marred  by  the  edges  of  the  cutting  tools. 

The  roll  illustrated  has  a  fair  assortment  of  useful  tools  of  good 
quality.  The  outfit  consists  of  two  screw  drivers,  two  pairs  of  pliers, 
two  chisels  and  one  center  punch,  three  drift  pins,  a  set  of  four  files, 
five  wrenches,  soldering  copper  and  handle,  a  file  handle,  a  split  pin 
extractor,  small  roll  of  wire  solder,  two  small  rolls  of  wire — one 
soft  iron  and  the  other  copper,  small  tin  boxes  containing  extra 
split  pins  or  locking  cotters  and  lock  washers,  and  a  ball  pein  hammer. 
The  wrenches  include  a  set  of  three  double  open-end  spanners,  one 


The  Modern  Gasoline  Automobile 


593 


adjustable   monkey   wrench,   and   a   pipe    wrench.     Small    and   large 
screw  drivers  are  provided  and  two  pairs  of  pliers,  one  for  handling 


Soldering  Coffer 

SoldenngCopper 
I       Chisel 


Fig.  359. — Tool  Roll  Suitable  for  Making  All  Ordinary  Repairs  on  Automobile 

Mechanism. 


594  The  Modern  Gasoline  Automobile 

flat  pieces  and  cutting  wire,  the  other  for  turning  round  pieces  are 
included. 

In  addition  to  the  tools  shown  in  the  outfit  depicted  at  Fig.  359,,  a 
motorist  who  intends  to  make  his  own  repairs  will  find  those  shown  at 
Fig.  360  very  useful.  The  valve-spring  lifter  is  employed  to  com- 
press the  valve  spring  when  it  is  desired  to  remove  the  locking  key 
or  washer  from  the  bottom  of  the  valve  stem,  and  will  be  found  very 
useful  when  the  valves  are  to  be  removed  for  cleaning  or  grinding. 
The  tinner's  snips  can  be  utilized  to  advantage  in  cutting  sheet  metal, 
packings,  asbestos  brake  lining  fabrics,  stock  for  shims  and  many 
other  purposes.  The  hack  saw  and  a  number  of  extra  blades  will  be 
found  of  value  when  it  is  desired  to  cut  bars  of  brass,  steel,  or  iron, 
and  it  can  be  used  in  cutting  wood,  fiber,  hard  rubber,  and  other 
materials  as  well.  The  adjustable  end  wrench  should  be  supplied  in 
two  sizes,  a  six  inch  for  small  work  and  one  eight  inches  long  for  use 
on  larger  objects.  This  form  of  wrench  is  especially  desirable  for 
motor-car  use  as  the  opening  between  the  jaws  may  be  altered  to  suit 
requirements,  and  the  angle  of  the  head  may  be  varied  so  it  will  work 
in  some  very  inaccessible  places  where  the  ordinary  forms  of  monkey 
wrench  or  open-end  spanner  could  not  be  employed. 

A  complete  file  set  is  an  almost  indispensable  part  of  the  equip- 
ment and  this  should  include  members  of  square,  round,  triangular, 
and  rectangular-  sections,  in  order  to  form  various  surface  profiles 
needed  on  motor-car  parts.  The  flat  files  are  usually  used  for  smooth- 
ing straight  surfaces,  and  the  round  and  half  round  are  employed 
on  curved  pieces.  The  square  file  and  the  "  three-square  "  or  "  three- 
cornered"  file,  as  it  is  often  called,  are  very  useful  in  filing  work 
where  sharp  corners  must  be  left.  In  choosing  files,  one  has  almost 
as  much  latitude  as  in  selecting  other  tools  because  they  are  made 
in  various  lengths  and  with  different  degrees  of  cutting  power.  In 
purchasing  files,  it  should  be  remembered  that  the  finer  grades  are 
used  only  for  finishing,  while  those  having  coarser  teeth  are  employed 
for  roughing  out  work  and  removing  metal.  The  file  set  should 
include  in  addition  to  the  forms  shown  a  small  fine  flat  file,  about 
the  size  of  a  manicuring  file,  for  fine  work  on  the  platinum  points 
of  spar.k-coil  vibrators  or  magneto-contact  breakers.  Files  should 
be  carried  in  cloth  or  leather  cases  or  wrapped  in  heavy  paper  so 


595 


596  The  Modern  Gasoline  Automobile 

that  the  cutting  surfaces  will  be  kept  clean  and  away  from  other 
objects. 

The  gasoline  blow  torch  forms  part  of  the  soldering  outfit  and 
can  be  used  to  advantage  in  heating  the  soldering,  copper.  It  is 
also  useful  in  heating  nuts  or  bolts  that  have  become  rusted  in  place, 
and  as  the  flame  is  very  hot  the  ends  of  small  rods  may  be  heated 
sufficiently  so  that  they  may  be  bent  into  eyes  or  rod  ends  very 
easily.  A  small  hand  drill  with  a  number  of  common  sizes  of  drills 
ranging  from  a  No.  60  to  about  five  sixteenths  of  an  inch  in 
diameter  can  be  used  so  often  in  fitting  small  brackets,  drilling  holes 
in  wood  or  metal,  drilling  out  broken  bolts  or  studs,  and  many  other 
uses,  that  it  will  soon  pay  for  itself.  A  wire  brush  is  useful  in  tire 
work,  where  it  can  be  used  to  roughen  up  the  surfaces  of  the  tube 
and  patch  before  cementing  or  vulcanizing  and  for  removing  dirt, 
carbon,  or  solidified  oil  from  the  mechanism  and  for  cleaning  the  teeth 
of  files. 

A  set  of  carbon  scrapers  may  be  included  with  advantage  in  the 
outfit  because  these  are  formed  in  such  a  way  that  much  of  the  carbon 
deposit  that  accumulates  in  the  combustion  chamber  may  be  removed 
through  spark  plug  and  valve  cage  openings  by  their  use  without  dis- 
mantling the  engine.  A  small  bench  vise  that  can  be  clamped  to 
the  running  board  of  the  car  is  of  value  when  filing  or  fitting  pieces 
that  could  not  be  held  properly  with  a  pair  of  pliers.  A  small  hand 
vise  is  also  useful,  as  this  will  grip  pieces  of  wire  or  sheet  metal 
stock  much  firmer  than  a  pair  of  pliers,  and  as  the  jaws  can  be 
clamped  together  by  a  winged  nut  no  effort  is  required  to  hold  the 
work,  which  is  so  securely  held  that  it  may  be  filed  or  hammered 
without  dislodging  it  from  the  jaws  of  the  vise. 

In  addition  to  the  tools  shown  a  lead-  or  copper-headed,  or  reen- 
forced  rawhide  leather  hammer  may  be  included,  as  this  can  often 
be  applied  for  driving  bolts  in  and  out  without  damaging  the  thread 
or  for  use  against  finished  parts  because  it  will  not  mar  the  surface. 
A  set  of  socket  or  box  wrenches  and  handle  will  be  found  useful  in 
reaching  bolt  heads  and  nuts  which  are  in  inaccessible  locations,  and 
it  is  often  desirable  to  supplement  the  two  or  three  sizes  of  fixed 
spanners  or  S  wrenches  usually  furnished  in  a  tool  roll  by  a  number  of 
other  sizes  which  will  permit  one  to  handle  practically  all  standard 


The  Modern  Gasoline  Automobile  597 

nuts.  A  set  of  five  may  be  obtained  that  will  fit  all  sizes  of  bolts  from 
three  sixteenths  of  an  inch  to  one  half  inch,  as  ten  milled  openings 
are  supplied  which  will  handle  bolt  heads  or  nuts  from  three  eighths  of 
an  inch  to  fifteen  sixteenths  of  an  inch  in  diameter. 

A  ratchet  wrench  that  will  fit  the  spark  plug  and  one  that  will 
fit  the  nuts  on  the  tire  lugs  have  important  advantages.  With  this 
form  of  wrench,  after  the  box  or  end  is  placed  over  the  nut  of  bolt 
head,  it  is  not  necessary  to  remove  the  wrench  each  time  the  handle  is 
moved.  The  amount  of  movement  permitted  will  vary  with  the  con- 
ditions and  sometimes  will  be  only  fifteen  or  twenty  degrees.  With 
a  ratchet  the  handle  is  brought  back  to  the  starting  point  without 
moving  the  nut  because  the  ratchet  mechanism  only  holds  in  one 
direction.  These  wrenches  are  time  savers  wherever  they  can  be  used. 

A  word  of  caution  to  motorists  who  are  apt  to  judge  tools  merely 
by  the  price  should  be  heeded.  Many  men  who  are  not  mechanically 
informed  select  even  the  simpler  tools  by  price  rather  than  quality. 
As  a  rule  the  better  quality  tools  only  cost  a  few  cents  more  and  will 
give  satisfactory  service  during  a  lifetime,  while  cheaper  ones  often 
cannot  endure  the  work  of  a  single  season.  Cheap  chisels  and  punches 
are  made  of  soft,  improperly  tempered  steel;  cheap  wrenches  are 
made  from  malleable  iron  castings,  instead  of  steel  drop  forgings; 
low-priced  screw  drivers  have  the  blades  of  inferior  stock  and  so 
flimsily  secured  in  the  handle  that  they  will  turn  on  the  slightest 
provocation  instead  of  loosening  the  screw  to  which  they  are  applied. 
The  motorist  who  buys  cheap  tools  is  penny  wise  and  pound  foolish 
and  it  is  better  to  purchase  fewer  tools,  but  good  ones,  if  economy 
dictates  when  the  purchase  is  made. 

General  Supplies  and  Spare  Parts. — In  addition  to  the  tools  enu- 
merated there  are  many  miscellaneous  appliances  that  can  be  carried 
to  advantage.  Some  of  these  are  necessary  only  with  certain  types 
of  cars,  and  many  of  the  list  which  follows  may  be  kept  at  home  except 
when  the  car  is  taken  on  an  extended  tour  which  is  apt  to,  end  at  some 
distance  from  a  convenient  base  of  supplies.  The  group  given  at 
Fig.  361  has  been  selected  because  it  shows  many  articles  of  equipment 
that  have  real  value. 

Funnels  to  fit  the  water,  gasoline,  and  oil  containers  should  be 
carried  and  it  is  well  to  use  separate  funnels  for  water,  oil,  and 


598 


The  Modern  Gasoline  Automobile  599 

gasoline.  That  used  for  water  should  have  a  spout  the  full  size  of  the 
filler  opening  in  the  radiator  and  it  is  desirable  that  it  should  include 
a  wire  gauze  screen  to  filter  the  water  of  any  particles  of  foreign 
matter  that  might  clog  the  circulating  system.  The  oil  funnel  should' 
be  small  and  it  can  be  easily  carried  by  nesting  in  one  of  the  larger 
funnels.  Sometimes  a  nest  of  three  funnels  may  be  obtained,  one 
fitting  in  the  other,  and  the  entire  set  of  three  takes  no  more  room 
than  one  funnel  would  ordinarily.  The  gasoline  funnel  should  have  a 
chamois  skin  through  which  all  fuel  would  pass  when  filling  the 
tank.  This  will  remove  the  water  and  dirt  always  present  in  gasoline 
and  is  practical  insurance  against  carburetion  troubles. 

A  collapsible  rubber  water  pail  is  useful  on  all  types  of  cars,  as 
it  may  be  used  to  replenish  the  supply  in  the  radiator  from  any  way- 
side source  when  on  the  road  or  to  carry  water  to  the  car  for  washing 
hands  after  repairs  have  been  made.  A  small  box  of  some  good  grease- 
dissolving  hand  soap,  a  clean  towel  and  a  piece  of  toilet  soap  take 
so  little  space  that  they  can  be  stowed  away  anywhere,  and  their  value 
•is  only  apparent  when  a  particularly  dirty  job  of  tire  replacement 
or  car  repairing  has  been  necessary  on  the  road.  A  hand  oil  can  and 
an  oil  syringe  are  needed  to  lubricate  the  various  parts,  the  syringe 
being  especially  valuable  to  force  oil  at  points  that  would  not  be 
easily  reached  with  the  hand  oiler  or  that  would  require  more  lubri- 
cant than  could  be  conveniently  supplied  by  that  method.  A  com- 
bination funnel  and  measure  is  often  carried  in  place  of  an  oil 
funnel. 

It  is  well  to  carry  a  gallon  can  of  cylinder  oil  and  a  small  can  of 
cup  grease  any  time  that  one  is  touring  away  from  home  when  there 
might  be  doubt  of  obtaining  the  same  grade  generally  used  on  the 
car.  With  the  ordinary  single-chamber  type  of  gasoline  tank  it  will  be 
found  advantageous  to  carry  a  spare  container  holding  two  gallons  of 
fuel.  This  occupies  but  little  space  and  is  practical  insurance  against 
being  stalled  by  lack  of  fuel.  Calcium  carbide  and  a  pair  of  extra  gas 
burners  should  be  carried  if  the  car  is  lighted  by  acetylene  gas  from 
a  generator,  and  extra  Tungsten  bulbs  if  the  car  is  electrically 
lighted.  A  small  hand  search  light  is  useful  in  looking  at  the  gaso- 
line level  at  night  or  in  inspecting  various  points  about  the  car  where 
the  presence  of  gasoline  fumes  would  make  the  use  of  a  naked  flame 


600  The  Modern  Gasoline  Automobile 

dangerous.  For  more  extended  working  after  nightfall,  a  small  port- 
able trouble  lamp,  which  will  take  its  current  from  the  ignition  battery, 
will  often  demonstrate  its  worth. 

The  character  of  the  spare  parts  needed  will  depend  entirely 
upon  the  make  of  car,  and  any  component  must  be  chosen  with 
reference  to  the  weaknesses  of  the  machine  under  consideration. 
The  selection  of  the  smaller  parts  for  replacement  should  be  by  an 
experienced  person  who  has  had  opportunity  to  study  that  make  of 
car.  It  is  well  to  have  a  spare  valve  complete  with  the  spring  re- 
tention collars  and  locking  key  on  any  make  of  car.  At  the  present 
time  practically  all  motor  cars  use  valves  that  are  interchangeable, 
and  but  one  set  for  replacement  is  necessary.  If,  however,  the  valves 
are  different  sizes  it  is  well  to  carry  one  each  of  the  exhaust  and  in- 
take. It  is  not  necessary  to  carry  these  around  on  ordinary  trips 
and  they  are  merely  provided  as  a  safeguard  when  touring  away  from 
a  base  of  supply.  It  is  well  to  carry  at  all  times  assortments  of 
small  parts  that  are  easily  lost,  such  as  split  pins,  lock  washers,  set 
screws,  taper  pins,  cap  screws,  semifinished  hex  nuts,  some  copper  and 
iron  washers,  and  a  few  carriage  bolts  of  the  sizes  used  in  securing 
the. fenders  to  the  irons  or  the  running  boards  to  the  hangers.  A 
roll  of  soft  iron  wire  and  a  roll  of  electric  tape  are  very  useful  in 
general  repair  work  and  rubber  tubing  may  be  included  with  advan- 
tage for  repairs  either  to  the  gas  piping,  conveying  acetylene  gas  to 
the  lamps  or  the  fuel  line,  leading  from  the  gasoline  tank  to  the 
carburetor. 

Some  of  the  supplies  needed  that  need  not  be  carried  on  the  car 
are  a  box  of  valve-grinding  compound,  asbestos  cord  and  candle 
wicking,  several  sheets  of  emery  cloth  and  sand  paper,  and  a  supply 
of  spare  gaskets  or  packing  material,  if  these  are  used  on  any  portion 
of  the  power  plant.  If  battery-and-coil  ignition  is  used  it  is  well 
to  carry  a  spare  set  of  batteries,  extra  primary  and  secondary  wire, 
battery  connectors  and  terminals,  and  either  a  complete  coil  unit  or 
parts  enough  to  make  up  a  complete  vibrator.  If  ignition  is  by  a 
high-tension  magneto,  a  complete  set  of  the  most  important  brushes 
and  contact-breaker  parts  may  be  obtained  at  small  cost  from  the  | 
manufacturer.  No  matter  what  kind  of  an  ignition  system  is  sup- 
plied if  is  well  to  carry  a  complete  set  of  spark  plugs.  These  mem- 


The  Modern  Gasoline  Automobile  601 

bers  are  liable  to  give  considerable  trouble  and  it  is  much  better  to 
replace  a  defective  member  with  a  new  one  rather  than  attempt  to 
repair  a  poor  spark  plug  on  the  road. 

Spare  oiler  and  fan  belts  are  useful  if  either  the  mechanical  oiler 
or  cooling  fan  are  driven  in  this  manner.  A  complete  set  of  tire 
tools  and  suitable  equipment  for  tire  repairing,  such  as  considered  in 
another  chapter,  should  be 'provided.  It  is  well  to  carry  all  smaller 
screws  and  parts  in  envelopes  or  small  boxes  which  should  be  plainly 
marked  so  the  contents  could  be  ascertained  at  a  glance  without  re- 
quiring examination.  Any  brightly  finished  steel  part  liable  to  rust 
should  be  covered  with  grease  and  wrapped  in  cloth  or  paper.  All 
goods  made  of  rubber  should  be  wrapped  up  to  protect  them  from 
oil,  which  has  a  harmful  effect.  Spark  plugs  may  be  carried  in 
wooden  or  leather  cases  and.  they  should  be  wrapped  in  such  a  way 
that  they  will  not  be  jarred  around,  as  this  is  liable  to  break  the  in- 
sulation or  bend  the  sparking  points. 

One  of  the  various  forms  of  jacks  shown  at  Fig.  362  should  be 
included  in  the  equipment.  This  member  really  forms  part  of  the 
tire-repair  outfit,  though  they  are  used  on  many  occasions  in  making 
repairs  when  the  tires  are  not  at  fault.  The  form  at  A  is  a  simple 
lever-operated  type  having  a  double  .ratchet.  A  series  of  short 
strokes  will  raise  the  lifting  ram,  while  slightly  altering  the  magni- 
tude of  the  stroke  will  allow  the  lifting  ram  to  fall.  In  the  jack 
shown  at  B  the  lifting  ram  is  raised  by  means  of  gearing  enclosed 
in  the  body  of  the  jack.  This  is  turned  by  means  of  a  socket  wrench, 
having  a  handle  similar  to  a  bit  brace.  In  the '  form  outlined  at  C 
the  lifting  ram  has  a  screw  thread  cut  on  it  and  is  raised  by  a  bevel 
gear  worked  by  a  hand  lever,  which  includes  the  ratchet  mechanism. 
A  very  substantial  form  of  direct  lift  jack  is  shown  at  D.  The  type 
outlined  at  E  is  used  to  raise  the  wheels  from  the  ground  quickly  and 
easily  and  is  intended  for  garage  use.  These  are  sold  in  sets  of  four 
and  are  used  by  many  motorists  to  raise  the  wheels  from  the  ground 
and  relieve  the  tires  of  the  car  weight  when  the  vehicle  is  not  liable 
to  be  used  for  a  few  days  or  a  longer  period.  The  selection  of  a  suit- 
able jack  is  important,  and  while  almost  any  form  will  be  adequate 
to  raise  a  light  car  the  motorist  should  be  sure  that  that  used  in 
connection  with  a  heavy  vehicle  has  ample  capacity  and  that  it  is  made 


602 


The  Modern  Gasoline  Automobile 


of  steel  instead  of  treacherous  iron  castings,  such  as   incorporated 
in  the  cheaper  jacks. 

Among  some   of  the  miscellaneous   supplies   that  will  he  found 
useful  may  be  mentioned  rawhide  lacing,  fan  belt  connectors,  leather 


Fig.  362. — Leading  Types  of  Car-Raising  Jacks. 


straps,  dry  powder  fire  extinguisher,  hose  clamps,  brass  polish  and 
polishing  cloths,  covers  of  rubber  or  fabric  for  the  lamps  to  protect 


The  Modern  Gasoline  Automobile  603 

them  in  wet  weather  and  chain  grips  for  the  tires.  If  a  cone  clutch 
of  the  leather-faced  type  is  used  some  clutch  compound  will  be  useful 
in  event  of  harsh  action  or  fuller's  earth  if  the  clutch  slips.  An 
emergency  spring  repairer,  which"  comprises  a  steel  forging  and  two 
clamps,  enables  one  to  make  a  broken  spring  operative  and  may  be 
found  of  advantage  if  the  car  is  operated  over  rough  roads  without 
shock  absorbers.  A  coil  of  rope  should  be  carried  on  any  car  that  is 
to  tour  in  comparatively  unsettled  countries,  and  special  rope  made 
especially  for  motorists'  use  may  be  obtained  from  the  supply  houses. 
These  include  thirty  or  forty  feet  of  one  half  or  three  quarter  inch 
diameter  Manila  rope,  fitted  with  a  heavy  galvanized  iron  hook  for 
attaching.  The  rope  may  be  used  for  towing,  in  connection  with  a 
"  Spanish  Windlass "  for  pulling  the  car  out  of  mud  holes  and 
ditches,  for  binding  a  rear  wheel  to  get  increased  traction  when 
that  member  drops  in  a  mud  hole,  and  for  securing  trunks  and 
packages  to  the  running  boards  or  other  portions  of  the  car. 

It  should  be  noted  that  the  equipment  advised  is  more  than  ordi- 
narily complete  and  it  is  not  likely  that  any  motorist  will  need  more 
than  the  articles  mentioned,  and  the  majority  will  be  able  to  get 
along  very  well  with  much  less.  Many  of  the  supplies  enumerated 
need  not  be  carried  on  the  car  except  "when  away  from  home,  but 
it  is  well  at  all  times  to  have  a  complete  outfit  of  tools  and  tire  repair 
appliances  as  well  as  necessary  spare  parts  for  eliminating  tire 
troubles  or  engine  derangement. 

How  Supplies  May  Be  Carried. — A  problem  with  many  motorists 
is  how  a  very  complete  outfit  may  be  stowed  on  the  average  car. 
The  views  at  Fig.  363  and  Fig.  364  show  how  this  difficulty  has  been 
solved  on  some  of  the  leading  automobiles  of  various  types.  At  A 
the  entire  outfit  necessary  for  tire  restoration  is  carried  at  the  back  end 
of  the  car  between  the  rear  springs.  The  trunk  case  serves  as  an 
anchorage  for  two  or  three  spare  casings  while  the  inner  tubes  and 
tire  repair  outfits,  as  well  as  many  of  the  general  supplies,  are 
easily  stowed  away  in  the  trunk.  In  the  view  of  the  rear  end  of 
the  car  shown  at  B  a  large  tool  box  is  placed  back  of  the  gasoline 
tank  and  has  ample  capacity  to  carry  all  tools  and  repair  parts  that 
would  be  needed  for  ordinary  repairing.  As  the  gasoline  tank  is 
carried  back  of  the  seat  there  is  room  under  the  front  seat  for  many 


604 


The  Modern  Gasoline  Automobile 


supplies.     The  form  of  trunk  used  in  carrying  clothing  when  on  a 
tour  is  outlined  at  C.     The  trunk  serves  merely  as  a  container  and 


Trunk 


Fig.  363. — Some  Conventional  Methods  of  Storing  Supplies  and  Equipment. 

protector  for  the  standard  size  suit  cases  that  are  employed  to  hold 
the  clothing  or  supplies. 

At  Fig.  364,  A,  the  very  ingenious  manner  in  which  a  prominent 
maker  has  utilized  the  space  back  of  the  seat  of  the  torpedo  roadster 
for  stowing  suit  cases  is  shown.  To  gain  access  to  these  the  front 
seats  are  pushed  forward,  the  center  partition  between  the  seats  is 
raised,  and  the  seat  back  is  allowed  to  fall.  The  result  is  that  a  large 
opening  \is  provided  through  which  the  suit  cases  or  .other  bulky  sup- 
plies may  be  easily  placed  in  the  body  compartments.  In  this  the 


The  Modern  Gasoline  Automobile 


605 


spare  tires  are  carried  at  the  rear  end  of  the  car  while  the  tools  that 
are  apt  to  be  often  used  are  stowed  away  in  an  easily  reached  chest 
on  the  running  board  of  the  car. 


Fig.  364. — How  Two  Leading  Motor  Car  Manufacturers  Made  Provision  for 
Carrying  Spare  Tires  and  Other  Supplies. 

At  Fig.  364,  B,  the  special  cage  provided  for  stowing  away  spare 
casings  on  late  models  of  Knox  cars  is  shown.     This  container  is  of 


606 


The  Modern  Gasoline  Automobile 


metal  and  access  to  its  interior  is  obtained  by  releasing  the  catch  and 
sliding  the  two  semicircular  doors  around  to  the  back  end.  This 
view  also  shows  the  form  of  trunk  rack  provided  on  many  touring 
cars  to  take  the  automobile  trunk  shown  at  Fig.  363,  C.  Two  views 
which  show  the  practical  disposition  of  the  various  accessories  on 
conventional  touring  cars  are  shown  at  Fig.  365.  A  side  elevation 


Fig.  365. — Side  Elevation  and  Plan  View  of  Modern  Motor  Car  Showing  Disposi- 
tion of  Various  Articles  of  Equipment  without  Hampering  Passengers  or 
Reducing  Carrying  Capacity. 

and  a  plan  view  of  the  vehicle  is  given,  and  the  location  of  the  es- 
sential accessories  and  supplies  are  so  clearly  shown  that  it  would 
seem  unnecessary  to  describe  these  in  detail.  The  placing  of  the 
lamps,  warning  signal,  wind  shield,  top,  spare  casings,  and  various 
cases  for  stowing  away  the  smaller  parts  may  be  readily  ascertained 
by  a  study  of  the  illustrations. 


CHAPTER    XII 

Operating  Advice  and  Explanation  of  Automobile-Control  Methods — Utility 
of  Spark  and  Throttle  Levers — Obtaining  Various  Speed  Ratios  with 
Friction  Transmission — How  Planetary  Gearsets  are  Controlled — Shift- 
ing Sliding  Gears  by  Progressive  and  Selective  Systems — Standard  Auto- 
mobile-Control Systems  Described  in  Detail — Maintenance  Hints  of  Value 
— Suggestions  for  Oiling — Winter  Care  of  Automobiles. 

THE  basic  principles  of  gasoline-motor-car  operation  are  prac- 
tically the  same  in  all  types  of  cars,  though  the  various  forms  of 
speed-changing  mechanism  demand  distinctive  methods  of  control  in 
each  specific  case.  It  is  not  possible  to  give  definite  information  that 
will  apply  to  controlling  all  types  of  cars,  but  the  general  advice 
given  can  be  applied  to  all  cars,  especially  the  instructions  relating 
to  the  method  of  motor-speed  control.  The  methods  of  regulating 
the  motor  speed  will  be  the  first  point  considered;  then  the  control 
system  when  the  simpler  forms  of  transmission  are  used,  and  finally 
the  method  of  obtaining  various  speed  ratios  with  sliding  gearsets. 

How  the  Motor  Should  Be  Started.- — One  of  the  most  important 
points  in  the  education  of  the  novice  motorist  is  the  best  method 
of  starting  the  motor  if  a  self-starting  device  is  not  provided.  Be- 
fore the  engine  is  set  in  motion  certain  precautions  must  be  observed 
regardless  of  the  make  or  type  of  car.  The  gasoline  tank,  radiator, 
and  lubricating-oil  container  should  be  inspected  to  make  sure  there 
is  enough  fuel,  water,  and  lubricating  oil.  The  shut-off  valve  in 
the  pipe  line  leading  from  the  gasoline  tank  to  the  carburetor  is 
opened  so  the  fuel  will  flow  to  the  vaporizer.  The  carburetor  should 
be  primed  by  means  of  a  small  plunger  usually  carried  in  the  float- 
bowl  cover,  and  if  a  small  resistance  is  felt  to  the  downward  move- 
ment of  the  primer  or  if  gasoline  escapes  from  the  bottom  of  the 
mixing  device,  this  may  be  considered  a  positive  indication  the  fuel 
from  the  tank  has  reached  the  carburetor  and  that  gasoline  is  present 
at  the  spray  orifice.  The  next  step  is  to  see  •  that  the  change-speed 

607 


608  The  Modern  Gasoline  Automobile 

lever  is  in  a  neutral  position  or  that  the  clutch  pedal  is  disengaged. 
The  spark-control  lever,  which  is  usually  carried  on  the  steering 
wheel,  should  be  set  at  the  full  retard  point.  In  some  cars  this  may 
be  at  the  back  of  the  sector,  while  the  retard  position  may  be  the  other 
extreme  in  other  motor  cars. 

If  one  attempts  to  set  an  engine  in  motion  by  means  of  a  hand 
crank  with  the  spark  lever  advanced .  so  that  an  early  spark  is  ob- 
tained, the  motor  may  "  kick  back,"  and  this  reversal  of  motion,  which 
is  due  to  premature  combustion,  may  sprain  the  wrist  or  break  an 
arm.  It  will  be  well  to  open  the  throttle  or  gas  lever  a  little  to 
insure  that  a  charge  of  combustible  gas  will  be  inspired  into  the  motor. 
The  engine  should  be  turned  over  several  times  as  briskly  as  possible, 
and  then  the  switch  which  completes  the  electrical  circuit  between 
the  battery  and  the  ignition  mechanism  should  be  put  into  circuit 
and  the  switch  plug  inserted.  The  hand  crank  is  pushed  in  until  it 
engages  a  ratchet  member  on  the  front  end  of  the  crank  shaft,  and 
then  the  motor  should  be  turned  by  pulling  up  on  the  starting  handle 
with  the  left  hand. 

The  hand  crank  should  always  be  engaged  so  that  an  upward  pull 
will  be  necessary  to  turn  the  crank  shaft,  and  a  point  that  cannot 
be  too  firmly  impressed  upon  the  embryo  motorist's  mind  is  that  gaso- 
line engines  should  always  be  started  by  pulling  up  on  the  handle  of 
the  starting  crank,  never  by  pushing  down.  If  the  starting  handle 
has  been  properly  placed  and  the  engine  has  been  turned  over  enough 
without  the  switch  so  the  cylinders  hold  a  gas  charge,  and  the  switch 
circuit  is  closed  when  a  decided  resistance  is  felt  as  the  crank  is  turned, 
indicating  that  the  piston  in  the  cylinder  in  which  the  gas  charge  is 
about  to  explode  is  near  ing.  the  compression  point,  a  single,  quick, 
strong  pull  on  the  crank  should  be  sufficient  to  start  any  properly  ad- 
justed motor. 

Multiple-cylinder  engines,  especially  those  of  the  four-  and  six- 
cylinder  type,  are  started  much  more  easily  than  the  one-  and  two- 
cylinder  forms.  These  can  often  be  started  by  turning  the  starting 
handle  over  briskly  so  the  motor  will  take  in  gas  but  without  the 
switch  closing  the  electric  circuit.  To  start  the  motor  the  switch  is 
closed  and  a  spark  will  be  produced  in  the  cylinder  about  to  fire  (only 
in  cars  equipped  with  battery  ignition)  by  moving  the  spark  lever  from 


The  Modern  Gasoline  Automobile 


609 


one  end  of  the  sector  to  the  other.  As  soon  as  the  engine  becomes 
started  it  should  be  kept  from  racing  by  shutting  down  the  supply  of 
gas  to  the  point  where  the  motor  will  turn  freely  and  yet  slowly. 

Most  hydrocarbon  vehicle  motors  have  a  certain  degree  of  flexi- 
bility, i.  e.,  they  may  be  run  slow  or  fast,,  and  the  speed  may  be  ac- 
celerated or  cut  down  as  desired  within  a  range  from  200  revolutions 
per  minute  to  the  maximum,  which  will  vary  with  the  type  of  motor. 


Spark  Advance  Handle 


,  Throttle  Leuer  Knob 


Accelerator  Pedal 

Throttle  Control  Stem 


Gasoline  Supply  Pipe 


Fig.  366.— Parts  of  Motor  Control  System  of  Peerless  Car.  Spark  Advance 
Regulated  by  Small  Hand  Lever.  Gas  Supply  Controlled  by  Automatic 
Engine  Governor,  Accelerator  Pedal  or  Throttle  Lever  on  Steering  Wheel. 

This  is  an  important  advantage,  inasmuch  as  it  permits  one  to  regulate 
the  vehicle  speed  on  most  occasions  by  a  touch  of  the  throttle  alone. 
The  engine  speed  of  practically  all  automobiles  is  controlled  by  two 
ways,  though  usually  these  are  employed  in  conjunction.  One  of  these 
consists  of  varying  the  time  of  the  spark  in  the  cylinder,  the  other 
•regulating  the  amount  of  gas  supplied. 

A  typical  carburetor-control  system  is  shown  in  detail  at  Fig.  366. 


610  The  Modern  Gasoline  Automobile 

The  throttle,  in  this  case,  may  be  controlled  by  three  distinct  means, 
One  of  these  is  a  centrifugal  governor  which  shuts  off  the  gas  suppl} 
automatically  if  motor  speeds  exceed  a  certain  predetermined  point 
The  governor  may  be  temporarily  dispensed  with  by  pressing  down  or 
the  accelerator  pedal,  which  will  open  the  throttle  directly,  or  bj 
means  of  the  throttle  lever  carried  on  top  of  the  steering  column 
The  usual  method  of  driving  is  to  set  the  throttle  lever  at  a  poinl 
which  will  give  the  minimum  speed  desired  and  depend  upon  the  gov- 
ernor to  take  care  of  other  speed  fluctuations.  If  it  is  necessary  tc 
get  more  gas  than  the  governor  will  allow  to  pass,  the  accelerator  peda" 
can  be  used  to  operate  the  throttle  directly.  The  function  of  the 
spark  lever  is  to  regulate  the  time  of  sparking  to  the  point  best  suited 
to  the  needs  of  the  engine. 

The  question  of  motor-speed  regulations  seems  to  be  a  simpl( 
one,  but  many  motorists  learn  proper  methods  of  spark-  and  throttle- 
lever  placing  only  after  considerable  driving  experience  has  been  ob- 
tained. Motor-speed  regulation  depends  upon  two  factors.  First,  ad- 
vancing  the  time  of  sparking  to  the  most  efficient  point  after  th( 
engine  has  once  been  started,  and  secondly,  increasing  the  amount  oj 
mixture  supplied  the  cylinders.  The  spark  and  throttle  levers,  while 
designed  to  be  manipulated  independent  of  each  other,  usually  mov( 
with  a  certain  definite  relation.  It  would  not  be  good  practice  to  rur 
an  engine  with  the  spark  lever  way  advanced  and  gas-supply  throttle 
nearly  closed;  nor  would  good  results  be  obtained  if  the  spark  level 
was  retarded  and  the  throttle  opened  as  it  is  desired  to  increase  th( 
motor  speed.  It  is  not  difficult  to  understand  the  function  of  the 
throttle  lever  and  how  the  admission  of  more  gas  to  the  cylinders 
would  act  in  creating  more  power,  just  as  augmenting  the  steam  supplj 
to  a  steam  engine  will  increase  its  capacity. 

The  rules  for  manipulation  of  the  spark  lever  are  not  so  well  un- 
derstood. In  order  to  make  clear  the  reason  for  intelligent  manipula- 
tion of  the  spark  handle  there  are  certain  points  that  must  be  con- 
sidered. On  most  automobiles  there  is  a  position  of  the  spark  Iever3 
usually  at  the  center  or  intermediate  point  of  the  sector  over  which  it 
moves  which  corresponds  to  the  normal  firing  point.  If  the  spark 
lever,  is  not  advanced  beyond  this  position,  and  the  motor  is  turning 
over  slowly,  the  gas  in  the  cylinders  is  being  exploded  when  the 


The  Modern  Gasoline  Automobile  611 

pistons  reach  the  end  of  their  compression  stroke.  When  the  gas  is 
fully  compacted  the  explosion  or  power  obtained  from  combustion  is 
more  powerful  than  if  the  spark  fired  gas  which  was  not  compressed 
properly.  The  electric  spark  is  not  produced  at  the  exact  time  that 
the  motor  should  be  fired  at  all  speeds,  and  if  the  spark  was  supplied 
the  very  instant  of  full  compression  irrespective  of  the  speed  of  rota- 
tion, there  would  be  no  need  of  moving  the  spark  lever. 

Not  only  is  the  current  apt  to  lag,  but  it  takes  a  certain  definite 
amount  of  time  to  set  fire  to  the  gas.  It  requires  the  same  amount  of 
time  to  ignite  the  gas,  of  given  composition,  regardless  of  the  speed  of 
the  motor.  If  the  motor  is  only  turning  at  a  few  hundred  revolutions 
*per  minute  there  is  ample  time  to  ignite  all  gas  charges  positively,  but 
if  the  motor  speed  increases  and  the  explosions  occur  oftener,  then  one 
must  compensate  for  the  more  rapidly  occurring  combustion  periods 
by  arranging  to  start  igniting  the  gas  earlier  so  the  explosion  will 
occur  when  the  piston  is  at  its  highest  point  in  the  cylinder.  The 
compensation  for  lag  is  made  by  advancing  the  spark.  The  spark 
lever  on  the  steering  wheel  or  column  moves  a  commutator,  if  battery 
system  is  employed,  or  the  magneto-contact-breaker  box,  if  that  form 
of  current  producer  furnishes  the  ignition  energy.  The  amount  of 
spark  advance  needed  depends  on  engine -'speed  and  the  greater  the 
piston  velocity  the  more  the  spark  should  be  advanced. 

It  is  possible  to  advance  the  spark  lever  too  far,  and  when  this 
occurs  the  gas  is  exploded  before  the  piston  reaches  the  top  of  its 
stroke  and  premature  explosion  takes  place.  As  a  result  of  this  the 
upwardly  moving  piston  is  forced  to  overcome  the  resistance  exerted 
by  the  expanding  gas  of  the  ignited  charge  in  completing  the  remain- 
der of  the  compression  stroke,  and  before  it  will  return  on  the  power 
stroke.  The  injurious  back  pressure  on  the  piston  reduces  the  capac- 
ity of  the  motor  and  a  pounding  noise  similar  to  that  produced  by 
loose  motor  parts  gives  positive  indication  of  premature  ignition  due 
to  excessive  spark  advance. 

At  the  other  hand,  if  the  spark  lever  is  not  set  as  far  forward  as  it 
should  be,  the  explosion  may  be  late  because  of  the  "  retarded  spark." 
If  the  spark  occurs  late  in  the  cycle,  the  charge  is  not  fired  until  the 
piston  has  reached  its  highest  point  and  after  it  has  completed  a  small 
portion  of  its  downward  movement.  As  the  point  of  maximum  com- 


612  The  Modern  Gasoline  Automobile 

pression  is  passed  and  the  piston  moves  down  in  the  cylinder,  the 
size  of  the  combustion  chamber  augments  and  the  gas  begins  to  ex- 
pand again  before  it  ignites.  Owing  to  the  moderate  compression  the 
power  resulting  from  explosions  is  less  than  would  be  the  case  with  a 
higher  degree  of  compression.  To  secure  power  it  is  necessary  to 
supply  more  gas  to  the  cylinders.  Driving  with  a  retarded  spark  pro- 
duces heating  of  the  motor  and  is  wasteful  of  fuel. 

For  ordinary  running  the  spark  lever  is  usually  placed  about  mid- 
way of  its  travel  on  the  sector,  and  as  a  general  rule  an  engine  with 
magneto  ignition  does  not  require  the  frequent  manipulation  of  the 
spark  necessary  when  current  is  produced  by  chemical  means.  As 
the  engine  speed  increases  the  current  produced  by  the  magneto  is 
proportionately  augmented,  and  the  spark  lever  need  not  be  advanced 
from  the  center  position  except  under  conditions  which  permit  of 
exceedingly  high  engine  speeds. 

The  diagram  presented  at  Fig.  367  is  furnished  by  the  Cadillac 
Motor  Car  Company  to  owners  of  its  cars,  and  shows  the  position  of 
the  spark  and  throttle  levers  to  obtain  various  engine  speeds  when 
the  car  is  on  the  direct  drive.  At  five  miles  per  hour  the  throttle  is 
practically  closed  and  the  spark  lever  has  been  advanced  about  a 
quarter  of  the  way  down  the  segment.  To  obtain  a  speed  of  eight 
miles  per  hour  the  spark  lever  is  moved  to  the  point  on  the  steering- 
wheel  sector  indicated  by  the  letter  C.  The  throttle  lever  is  not  dis- 
turbed. Moving  the  spark  lever  about  two  thirds  of  the  way  on  the 
sector  will  increase  the  speed  of  the  car  to  nine  miles  per  hour.  From 
this  point  speed  ratios  are  augmented  by  moving  the  throttle  lever  and 
the  car  speed  increases  progressively  as  the  amount  of  gas  supplied  the 
engine  is  augmented.  For  higher  speeds  than  twenty-five  miles  pur 
hour  the  spark  and  throttle  levers  are  moved  toward  the  end  of  the 
sector  and  it  is  usual  practice  to  advance  both  in  conjunction  beyond 
this  point. 

Summing  up,  it  will  be  patent  that  the  greatest  economy  of  fuel 
will  result  when  the  car  is  driven  with  as  little  throttle  opening  as 
possible,  and  with  the  greatest  spark  advance  the  motor  speed  will 
allow.  To  obtain  maximum  power,  as  in  hill  climbing  on  the  direct 
drive,  the  spark  lever  should  never  be  advanced  beyond  center  and  the 
throttle  should  be  opened  as  wide  as  possible.  For  extreme  high 


5  Miles  per  hour 


12  Miles  per  hour 


8  Miles  per  hour 


9  Miles  oer  hour 


10  Miles  per  hour 


15  Miles  per  hour 


20  Miles  per  hour 


25  Miles  per  hour 


Fig.  367.— Position  of  Spark  and  Throttle  Control  Levers  on  Cadillac  Car  to  Ob- 

I  tain  Various  Car  Speeds  with  Gearing  in  Direct  Drive. 

613 


614  The  Modern  Gasoline  Automobile 

speeds,  the  throttle  should  be  advanced  to  a  point  about  midway  of  its 
travel  before  the  spark  lever  is  advanced  beyond  that  point.  If  this 
does  not  give  the  required  increase  in  speed,  the  spark  lever  should  be 
advanced  as  far  as  possible  and  the  amount  of  gas  increased,  by  mov- 
ing the  throttle  lever  from  its  central  position  to  the  extreme  position 
on  the  secte.  Control-lever  placing  varies  on  nearly  all  cars,  but  the 
most  commorw.position  is  on  top  of  the  steering  column,  where  they 
are  convenient  to  operate  and  very  accessible.  In  some  cars  the  spark 
and  throttle  levers  may  be  placed  under  the  steering  wheel  and  on  one 
side  of  the  steering  post,  one  being  located  above  the  other.  In  other 
vehicles,  they  are  disposed  under  the  wheel  and  on  opposite  sides  of 
the  steering  post.  Some  designers  do  not  furnish  variable  spark  when 
a  magneto  is  provided.  The  magneto  contact  breaker  is  advanced  to 
the  point  where  the  best  operation  under  average  conditions  is  at- 
tained, and  motor-speed  regulation  is  entirely  by  using  the  throttle 
lever  or  accelerator. 

Controlling  Cars  with  Friction  Transmission. — After  the  engine  has 
been  started  the  next  point  is  to  put  the  automobile  in  motion.  The 
means  for  obtaining  the  various  speed  ratios  will  determine  the  steps 
that  should  follow.  When  a  friction  or  planetary  transmission  is  in- 
stalled the  control  is  very  simple  and  usually  a  single  lever  suffices  to 
furnish  all  desired  speed  ratios.  The  Carter  Car  control  system  is 
shown  at  Fig.  368  and  is  a  good  example  of  the  simple  method  of 
control  possible  when  friction-disk  change-speed  gearing  is  utilized. 
One  hand  lever  at  the  side  of  the  car  serves  to  move  the  driven  mem- 
ber to  its  various  positions  on  the  face  of  the  driving  member.  The 
inner  foot  pedal  is  employed  to  bring  the  friction  disks  together  and 
establish  driving  contact  between  them  wThen  the  proper  speed  position 
has  been  selected  with  the  hand  lever.  The  other  pedal  is  used  to 
apply  a  running  brake  at  the  rear  wheels.  Motor  speed  is  regulated  by 
spark  and  throttle  levers  on  the  steering  wheel. 

With  this  form  of  control  the  friction  pedal  is  released  before  the  j 
engine  is  started  and  as  this  breaks  the  driving  connection  between  the 
friction  disks,  the  engine  can  be  turned  without  moving  the  vehicle. 
After  the  motor  is  started  in  the  manner  previously  indicated,  the 
speed-changing  lever  is  placed  at  a  position  about  midway  in  its  travel 
or  so  if  will  line  up  with  the  bulb  of  the  horn  shown  in  illustration. 


The  Modern  Gasoline  Automobile 


615 


This  gives  one  of  the  lowest  speed  ratios.  To  start  the  car  the  friction 
pedal  is  pressed  with  the  left  foot  until  sufficient  pressure  exists  to 
cause  the  driving  member  to  turn  the  driven  wheels  and  transmit  the 
engine  power  to  the  rear  wheels.  After  a  certain  degree  of  headway 


-Throttle 


Fig.  368. — Control  System  of  Carter  Car,  Which  Employs  Friction  Transmission. 

has  been  attained,  the  friction  pedal  is  allowed  to  return  to  its  free 
position  and  the  hand  lever  is  pushed  forward  a  few  inches  to  give 
a  slightly  higher  speed.  The  friction  pedal  is  again  depressed  and 


616  The  Modern  Gasoline  Automobile 

when  sufficient  pressure  is  exerted  the  car  will  move  forward  at  a 
higher  speed.  The  farther  forward  the  handle  is  placed,  the  higher 
the  vehicle  speeds,  and  if  the  handle  is  brought  back  beyond  a  central 
position  a  reverse  motion  is  obtained. 

The  friction  pedal  may  be  locked  at  any  desired  point  by  tilting 
the  foot  pad  up  by  raising  the  heel.  When  it  is  desired  to  stop  the  car 
the  friction  pedal  is  released  by  bearing  down  on  the  lower  portion 
of  the  foot  pad,  which  loosens  the  ratchet  lock  and  by  pushing  on  the 
brake  pedal.  It  is  important  that  the  friction  pedal  be  applied  grad- 
ually and  that  it  is  not  pressed  down  any  farther  than  is  necessary  to 
drive  the  car.  The  amount  of  pressure  will  depend  on  the  road  con- 
ditions, and  the  lighter  the  degree  of  pressure  the  less  wear  will  take 
place  on  the  friction-wheel  fiber  ring.  When  on  a  hill,  or  in  sand, 
the  friction  pedal  will  have  to  be  pushed  up  harder  than  when  the 
car  is  driven  on  a  level  highway  with  a  good  surface. 

Before  the  hand  lever  is  changed  from  one  position  to  another 
the  friction  pedals  should  always  be  released.  An  emergency  braking 
effect  may  be  obtained  by  pushing  the  hand  lever  in  reverse  position  and 
applying  the  friction  pedal  if  the  car  is  going  forward,  or  vice  versa, 
if  the  car  is  traveling  in  a  reverse  direction.  One  of  the  advantages 
of  the  friction  transmission  is  that  it  is  difficult  to  injure  it  by  care- 
less handling  because  there  are  no  gears  to  be  stripped  if  these  are  not 
meshed  properly.  The  transmission  is  practically  noiseless  and  speed 
changes  are  effected  easily  and  noiselessly. 

Planetary  Gears  Easily  Controlled. — One  of  the  advantages  of  the' 
planetary  gearset,  when  applied  in  the  two-speed  forward  and  re- 
verse forms  is  that  the  method  of  obtaining  the  various  speed  ratios 
is  very  simple  and  easily  understood.  At  Fig.  369  the  control  system 
of  some  of  the  lighter  Maxwell  cars  is  shown  and  the  various  positions 
of  the  lever  to  obtain  the  different  speeds  are  clearly  indicated.  On 
these  cars,  the  speed  of  rotation  of  the  double-cylinder  motor  is  regu- 
lated by  a  small  pedal  connected  to  the  throttle  of  the  carburetor  and 
a  spark  lever  at  the  top  of  the  steering  column,  under  the  steering 
wheel.  The  speed  changes  are  obtained  by  a  single  hand  lever  and 
the  hub  brakes  are  applied  by  the  usual  form  .of  pedal. 

Five  positions  of  the  handle  give  two  neutral  points,  one  reverse 
motiofr,  and  two  forward  speeds.  'Ordinarily  the  lever  is  in  an  ap- 


The  Modern  Gasoline  Automobile 


617 


proximately  vertical  position  and  is  at  the  neutral  point  between  the 
reverse  and  slow  speed.     When  pulled  back  from  this  position  a  re- 


Reverse 


Slow 


Throttle 


Change 
Speed  Lever 


Foot  Brake 


Fig.  369. — Simple  Speed-Regulation  Method  on  Maxwell  Cars  Furnished  with 

Planetary  Gearsets. 


L 


verse  motion  is  obtained.     If  pushed  forward  the  slow-speed  gears  are 
put  into  action.     Moving  the  hand  lever  from  the  slow-speed  position 


618  The  Modern  Gasoline  Automobile 

forward  gives  the  second  neutral  point,  while  the  high  speed  or  direct 
drive  is  obtained  by  pushing  the  lever  to  the  extreme  forward  position. 
The  lever  must  be  held  in  the  reverse  position  but  can  be  locked  into 
low  and  high  speeds. 

When  running  the  car  under  conditions  where  it  is  not  necessary 
to  go  into  the  reverse  the  lever  may  be  pulled  from  the  high-speed 
position  to  the  neutral  point  between  high  and  slow  speeds.  If  the 
car  is  stopped  it  can  be  easily  started  forward  again  by  pulling  the 
handle  back  into  slow  speed  from  neutral  position  and  then  forward 
to  engage  the  direct  drive.  If  the  handle  is  pulled  way  back  out 
of  high  speed  into  neutral  position  between  slow  and  reverse,  either  of 
these  ratios  may  be  easily  obtained.  A  point  necessary  to  consider 
when  operating  a  planetary  transmission  is  that  the  slow  and  reverse 
speed  must  be  applied  gradually  and  that  the  engine  be  speeded  up 
pretty  well  before  either  reverse  or  slow-speed  bands  are  tightened. 
After  the  car  has  attained  a  certain  degree  of  momentum  on  the  low 
speed  the  lever  should  be  put  forward  into  the  high-speed  position 
gradually  in  order  to  avoid  the  sudden  jump  which  always  obtains  when 
changing  from  the  low  to  the  high  speed  of  a  two-speed  car.  This 
jump  is  caused  by  a  sudden  acceleration  due  to  the  higher  gearing, 
provided  by  the  direct-drive  position  which  is  much  higher  than  the 
maximum  speed  permitted  by  the  slow-speed  gears. 

The  Ford  car  is  one  of  the  most  popular  of  moderate-priced  auto- 
mobiles and  over  100,000  of  the  Model  "  T  "  are  now  on  the  road. 
The  control  system  of  this  car  is  extremely  simple  and  yet  it  is  differ- 
ent from  that  of  any  other  automobile.  The  gearset,  which  has  been 
previously  described,  is  a  planetary  type  which  gives  two  forward 
speeds  and  a  reverse  motion.  The  conventional  form  of  steering 
wheel  is  used  to  control  the  direction  of  car  travel,  and  spark  and 
throttle  levers  are  mounted  on  the  steering  column  beneath  the  wheel 
to  control  the  speed  of  the  power  plant.  It  is  in  the  method  of  ob- 
taining the  various  speed  ratios  that  the  control  system  is  distinctive. 
As  will  be  seen  by  referring  to  Fig.  369,  A,  three  pedals  and  a  hand 
lever  are  provided  on  the  left  side  of  the  car.  The  pedal  on  the 
extreme  left  is  used  to  control  the  high-  and  low-speed  clutches  and 
is  marked  "  C."  That  next  to  it,  which  is  marked  "  K,"  is  used  to 
constrict  the  reverse  band  of  the  transmission  and  obtain  reverse 


The  Modern  Gasoline  Automobile 


619 


motion.     The  pedal  at  the  right,  which  is  provided  with  a  letter  "  B  " 
cast  on  its  surface,  is  used  to  apply  the  foot  brake. 

The  hand  lever  engages  the  high-speed  or  direct-drive  clutch  when 
thrown  forward   and   when   pulled   back   it   actuates   the   emergency 


Gasoline  Adjustment 


Steering  Wheel 


Emergency  Brake 
and  Clutch  Release 


High  and 
Speed  Clutch 


Reverse 


Spar! 


Gas 


Fig.  369  A. — Outlining  the  Distinctive  Control  System  of  Ford  Model  "  T  " 
Automobile,  Which  Employs  Two-Speed  and  Reverse  Planetary  Gearing. 
Location  of  Spark  and  Throttle  Levers  Clearly  Shown  in  Inset. 

brake.  An  interlocking  connection  is  provided  so  the  emergency 
brake  cannot  be  applied  without  releasing  the  direct-drive  clutch. 
The  lever  may  be  set  in  a  neutral  position  and  the  clutch  will  be 
released  without  applying  the  brake  when  it  is  approximately  vertical. 
When  the  high  speed  is  in  and  the  hand  lever  is  thrown  way  forward 
the  high-speed  clutch  may  be  released  by  a  light  pressure  on  pedal 
"  C  "  and  a  further  movement  of  this  pedal  will  apply  the  low  speed. 
Thus  one  pedal  gives  control  of  both  high  and  low  speeds  forward 


620  The  Modern  Gasoline  Automobile 

and  the  clutch  can  be  released  in  exactly  the  same  manner  as  that 
of  a  sliding-gear  car  when  it  is  desired  to  slow  up,  such  as  for  turning 
a  corner,  descending  a  hill  or  passing  another  vehicle. 

Before  starting  the  car  the  hand  lever  must  be  in  a  vertical  posi- 
tion, this  releasing  the  clutch  and  applying  the  emergency  brakes. 
To  start  the  car,  after  the  engine  has  been  started  in  the  usual  man- 
ner, the  foot  is  placed  on  the  clutch  pedal  to  keep  it  in  a  neutral 
position,  while  the  hand  lever  is  thrown  as  far  forward  as  it  will  go. 
The  engine  is  then  accelerated  and  the  clutch  pedal  is  pushed  for- 
ward until  the  slow-speed  band  tightens  around  the  drum  of  the 
transmission  and  the  car  gathers  headway  on  the  lower  ratio.  After 
it  has  attained  a  certain  momentum,  the  clutch  pedal  is  allowed  to 
drop  back  gradually  into  the  high-speed  position.  The  foot  may 
then  be  removed  until  such  times  that  the  clutch  must  be  discon- 
nected. Before  applying  the  foot  brake,  which  is  done  by  pressing 
with  the  right  foot  upon  the  pedal  marked  "  B,"  the  clutch  pedal 
should  be  put  in  neutral  position  with  the  left  foot. 

To  reverse  the  car,  it  must  first  be  brought  to  a  standstill.  The 
engine  is  kept  running  and  the  clutch  is  disengaged  with  the  hand 
lever,  which  is  placed  in  the  neutral  position  but  not  pulled  far  enough 
back  to  apply  the  emergency  brake.  The  reverse  pedal  marked  "  R  " 
is  then  pushed  forward  with  the  left  foot,  leaving  the  right  one  free 
to  use  on  the  brake  pedal  if  needed.  To  stop  the  car,  the  throttle  is 
closed  so  that  the  engine  will  not  race ;  the  high  speed  is  released  by 
pressing  the  clutch  pedal  forward  into  its  neutral  position  and  ap- 
plying the  foot  brake  slowly,  but  firmly,  until  the  forward  motion 
of  the  car  is  arrested.  It  is  imperative  that  the  foot  be  retained  on 
the  clutch  pedal  until  the  hand  lever  is  pulled  back  to  its  neutral 
position.  The  placing  of  the  spark  and  throttle  levers  is  clearly 
shown  in  the  inset  in  the  right-hand  corner  of  the  cut,  both  levers 
being  pulled  back  to  accelerate  the  motor  and  pushed  forward  to  slow 
it  down.  The  same  rules  previously  given  for  the  manipulation  of 
the  spark  and  throttle  levers  apply  just  as  well  to  this  make  of  car. 

In  the  Liberty-Brush  runabout  the  control  system  is  somewhat 
similar  to  that  previously  described,  except  that  the  hand  lever  at  the 
side  of  the  car  is  operated  selectively  rather  than  progressively.  The 
control  system  is  shown  at  Fig.  370,  and  in  the  upper  corner  of  the 


The  Modern  Gasoline  Automobile 


621 


illustration  the  different  positions  of  the  lever  in  the  gate  are  shown  to 
obtain  the  various  speeds  desired.  Engine  speed  is  controlled  by 
spark  and  throttle  levers  under  the  steering  wheel  in  the  usual  manner. 


Foot  Brake  and 

Clutch  Release 


Fig.  370. — Selective  Change-Speed  System  of  Liberty-Brush  Light  Runabout. 

The  lever  works  in  a  gate  arrangement  and  normally  is  in  the  position 
indicated  by  the  letter  N  in  the  inset.  In-  this  neutral  position  the 
hand  lever  is  normally  straight,  up  and  down. 

To  obtain  slow  speed  the  top  of  the  handle  is  pushed  out  and  the 
lever  moved  sideways  until  it  is  in  the  outer  slot.  The  lever  is  then 
pulled  back  until  a  distinct  resistance  is  felt,  at  which  time  the  slow- 
speed  band  will  be  clamped  around  the  slow-speed  drum  of  the  trans- 


622 


The  Modern  Gasoline  Automobile 


mission  and  the  gearing  contained  therein  be  in  action.     If  the  lever 
is  pushed  from  the  slow-speed  position  forward  until  another  resisting 


.Steering  Wheel 


Fig.  371.— Side-Control  Levers  and  Pedals  of  Fierce-Arrow  Sliding-Gear  Cars. 


The  Modern  Gasoline  Automobile  623 

influence  is  felt,  the  gearing  will  be  in  reverse  ratio.  To  engage  the 
direct  drive,  the  hand  lever  is  pulled  through  the  neutral  slot  and 
pushed  forward  in  the  inner  slot.  The  single-foot  pedal  not  only  acts 
t.o  apply  the  foot  brake,  but  will  automatically  disengage  the  high- 
speed clutch  before  the  brakes  are  applied  without  touching  the  hand 
lever.  In  driving  the  car  on  the  high  speed,  if  it  is  desired  to  slow  up 
to  pass  another  vehicle  or  turn  a  corner,  a  slight  pressure  on  the  pedal 
will  release  the  high  speed.  A  greater  degree  of  pressure  on  the  pedal 
will  apply  the  foot  brakes. 

Operating  Sliding  Gearsets. — Two  sliding  gear  systems  are  fitted 
to  motor  cars,  but  at  the  present  time  the  progressive  system  of  con- 
trol has  been  almost  entirely  superseded  by  the  selective  system.  The 
principles  of  operation  are  practically  the  same  as  relate  to  clutch 
operation  and  gear  engagement,  but  in  the  progressive  system  it  is 
necessary  to  move  the  gear-shift  lever  from  one  end  of  a  segment  to 
the  other  to  obtain  the  range  of  speed.  In  the  selective  system  a 
gate  segment  is  utilized  and  the  hand  lever  is  moved  only  short  dis- 
tances to  select  the  speed  required. 

The  control  system  of  a  typical  selective  sliding-gear  car  is  shown 
at  Fig.  371.  Engine-speed  regulation  is  by  spark  and  throttle  levers 
at  the  left  side  of  the  steering  wheel  operated  in  the  usual  manner. 
Two  pedals  are  provided  and  two  hand  levers.  The  pedal  that  is  to 
be  worked  by  the  left  foot  is  used  to  release  the  clutch,  while  that 
that  is  applied  by  the  right  foot  actuates  the  running  brake.  The 
outer  hand  lever  works  on  a  notched  segment  and  is  pulled  toward 
the  operator  to  apply  the  emergency  brake.  The  inner  lever  works  in 
a  gated  segment  and  is  employed  to  obtain  the  varying  speed  ratios. 
Another  complete  control  system  in  which  side  levers  are  employed 
with  all  parts  clearly  depicted  is  shown  at  Fig.  372.  These  may  be 
considered  representative  of  conventional  practice  and  the  majority 
of  the  sliding-gear  cars  are  controlled  in  practically  the  same  manner. 

How  Selective  Gearsets  are  Operated. — The  arrangement  of  guid- 
ing gates  which  are  used  with  selective  systems  of  gearset  control 
are  shown  at  Fig.  373.  In  all  of  these  the  neutral  point  is  usually  at 
the  center  of  the  bars  dividing  the  segment  into  slots  and  the  lever 
can  be  easily  moved  in  either  direction  to  engage  the  speed  desired. 
On  the  Peerless  cars,  which  are  provided  with  a  four-forward  speed 


624 


The  Modern  Gasoline  Automobile 


and  reverse  gearset,  there  are  three  positions  or  slots  for  the  speed 
changing  lever  at  the  front  end  of  the  segment  and  two  at  the  rear. 
To  engage  the  reverse  gear  the  lever  would  be  placed  in  the  slot  in- 
dicated by  the  letter  "  R."  To  give  the  lowest  forward  speed  the 
lever  would  be  pulled  out  of  the  reverse  slot  and  pushed  forward  into 
the  adjacent  one,,  indicated  by  number  one;  pulling  the  hand  lever 
back  out  of  this  slot,  into  that  marked  number  two  will  give  the  second 
speed.  To  engage  the  third  speed  the  shift  lever  would  be  jmlled  out 


JSpark 
Gas 


Fig.  372. — Complete  Control  System  of  Buick  Automobiles  Showing  Engine- 
Regulating  Levers  on  Steering  Wheel,  Enclosed  Hand  Levers  and  Foot 
Control  of  Clutch  and  Running  Brake. 

of  the  center  slot  and  into  the  outside  one  and  pushed  forward  until  it 
filled  the  slot  marked  three.  For  the  highest  speed,  the  hand  lever 
would  be*  jpulled  from  slot  three  to  the  outside  rear  slot  four. 

On  the  Locomobile  cars  a  four-speed  transmission  is  provided,  but 


The  Modern  Gasoline  Automobile 


625 


the  arrangement  of  the  control  slot  differs  somewhat  from  that  used 
on  the  Peerless  cars.  As  shown  in  the  cut,  the  lever  is  in  neutral 
position  and  can  be  moved  sideways  into  either  the  inner  or  outer 
slot.  To  obtain  the  reverse  speed  the  handle  is  pushed  as  far  forward 


Peer/e* 


Knox 


Fig.  373.— Change-Speed  Gates  for  Three-  and  Four-Speed  Selective  Trans- 
missions. 

in  the  outer  slot  as  it  will  go.  Pulled  back  from  this  position  but 
keeping  it  still  in  the  outer  slot  will  give  the  first  speed.  Pulling  the 
lever  back  from  point  indicated  by  one  to  slot  two  will  engage  the 
second  speed.  The  higher  ratios  are  obtained  in  the  inner  slot.  A 
forward  movement  of  the  lever  engaging  the  third  speed,  while  a  pull 
back  will  engage  the  highest  ratio. 

On  Knox  cars,  where  three  forward  speeds  are  provided,  the  guid- 
ing gate  is  arranged  in  such  a  manner  that  the  reverse,  first,  and 
third  speeds  are  obtained  by  pushing  the  lever  into  one  of  three  slots 
at  the  front  end  of  the  gate,  while  the  second-speed  gears  are  meshed 
by  pulling  the  hand  lever  back  into  the  one  rear  slot. 


626 


The  Modern  Gasoline  Automobile 


In  operating  a  car  with  the  selective  method  of  control  it  is  neces- 
sary that  the  gear-shift  lever  be  in  a  neutral  point  if  the  clutch  is 
engaged  before  starting  the  engine.  After  the  motor  has  been  started 
and  is  running  at  the  proper  speed,  and  it  is  desired  to  start  the  car, 
the  first  step  is  to  release  the  emergency-brake  lever  and  depress  the 


Steering  Wheel 


o       o       000|||        oo0 
Gear  Leuer-4\\  Accelerator 


Fig.  374.— Reo  Control  System  with  Single  Centrally  Located  Gear-Shift  Lever 
and  Steering  Wheel  on  Left  Side. 

clutch  pedal  so  that  the  driving  connection  between  the  engine  and 
gearset  is  interrupted.  With  the  clutch  pedal  depressed  fully  the 
hand  lever  is  pushed  into  the  slot  which  will  give  the  slowest  speed ; 
then  the  clutch  is  allowed  to  engage  slowly  and  the  start  forward  is 
made  on  the  lowest  speed.  After  a  certain  degree  of  momentum  has 
been  attained  the  clutch  pedal  is  again  depressed  and  the  speed  lever 


The  Modern  Gasoline  Automobile  .627 

shifted  into  the  next  higher  speed  ratio.  The  velocity  of  the  car  is 
thus  gradually  increased  by  moving  the  lever  in  steps  from  the  lowest 
to  the  highest  ratio.  With  any  form  of  sliding-gear  transmission  it 
is  imperative  that  the  clutch  be  released  every  time  a  change  of  speed 
is  to  be  made  and  the  clutch  should  not  be  engaged  again  until  the 
gearing  is  positively  in  mesh. 

When  one  desires  to  stop  the  car  the  first  step  is  to  release  the 
clutch  by  pushing  forward  on  the  clutch  pedal  with  the  left  foot  and 
apply  the  foot  brakes  with  the  right  foot.  The  gear-shift  lever  is 
brought  into  a  neutral  point  and  then  the  clutch  may  be  engaged 
again,  if  desired.  On  many  cars  the  emergency-brake  lever  and  clutch- 
shifting  mechanism  are  interlocked  in  such  a  manner  that  the  clutch 
is  released  automatically  when  the  hand-brake  lever  is  applied.  The 
emergency  brakes  of  the  average  car  are  seldom  used  in  normal  opera- 
tion, the  main  reliance  of  most  drivers  being  .foot-operated  service 
brakes.  When  it  is  desired  to  lock  the  car  the  emergency-brake  lever 
is  pulled  back  until  the  brakes  are  engaged  and  is  retained  in  that 
position  by  a  locking  ratchet  that  engages  suitable  teeth  cut  into  the 
brake-lever  segment. 

There  is  some  difference  of  opinion  regarding  the  placing  of  the 
steering  wheel  and  whether  it  should  be  on  the  right  or  left  side  of 
the  car.  Most  American  motor  cars,  which  originally  were  copies  of 
foreign  productions,  place  the  wheel  and  control  levers  at  the  right 
side  of  the  car,  because  they  were  disposed  in  this  manner  on  the 
European  cars  from  which  the  first  American  vehicles  were  copied. 
The  road  rules  in  Europe  are  different  than  in  this  country  in  that  a 
driver  has  to  pass  a  vehicle  going  in  the  same  direction  on  the  right 
and  must  keep  to  the  left  of  the  road.  This  made  the  right  hand 
placing  of  the  wheel  logical  and  desirable.  In  this  country,  however, 
the  rules  of  the  road  are  that  all  vehicles  must  keep  to' the  right  and 
when  one  passes  another  conveyance  going  in  the  same  direction  it 
should  be  passed  on  its  left  side.  This  makes  the  right-hand  control, 
which  is  logical  and  desirable  in  Europe,  unsuitable  for  road  laws  of 
this  country. 

To  be  logical  the  steering  wheel  of  American  cars  should  be  placed 
at  the  left  side  instead  of  the  right.  A  number  of  designers  follow 
this  rule,  but  in  order  to  conform  as  much  as  possible  with  American 


628 


The  Modern  Gasoline  Automobile 


practice  the  gear-shift  lever  is  placed  in  the  center  of  the  car  where 
it  can  be  operated  by  the  right  hand  instead  of  at  the  left  side.  A 
typical  left-hand  control  system  is  shown  at  Fig.  374.  In  this  a 
single-hand  lever  is  mounted  in  the  center  of  the  floor  board  and  is 
moved  in  four  directions.  It  may  be  rocked  to  the  right  or  left  and 
pulled  back  or  pushed  forward  in  either  of  these  positions.  When  the 


Clutch  PedQl 


Liver 


Fig.  375. — Speed-Change  Levers  of  Knox  Cars.- 

lever  is  straight  up  and  down  it  is  at  the  neutral  point,  the  three 
forward  speeds  and  reverse  motion  are  obtained  by  rocking  the  lever 
from  side  to  side  and  pushing  it  forward  or  backward  as  conditions 
demand.  Two  pedals  are  provided.  That  at  the  extreme  left  serves 
to  release  the  clutch  and  apply  the  service  brake,  while  the  one  oper- 


The  Modern  Gasoline  Automobile 


629 


ated  by  the  right  foot  actuates  the  emergency  brakes.     When  a  single 
pedal  is  used  for  service-brake  application  and  clutch  release,  it  is 


Steering  Wheel 
Engine  Control  Leuers 


Emergency  Brake  Leuer 


Fig.  376. — Complete  Control  Group  of  Mitchell  Motor  Cars. 

depressed  about  half  its  travel  to  disengage  the  clutch  and  applies  the 
running  brake  from  that  point  to  the  end  of  its  radius  of  movement. 


630 


The  Modern  Gasoline  Automobile 


Many  designers  who  favor  the  right  hand  placing  of  the  steering 
post  locate  the  gear  shift  and  emergency-brake  levers  in  the  center  of 
the  floor  in  order  that  the  torpedo  body,  with  which  the  cars  are  fitted, 
may  present  an  unbroken  and  smooth  appearance  without  any  pro- 
jecting part  or  levers  when  viewed  from  either  side.  The  placing  of 


Muffler 


Gear  Lever 


Fig.  377. — Center  Control  Levers  of  Jackson  Cars  and  Pedals  for  Clutch-Running 
Brake,  Accelerator  and  Muffler  Cut-Out  Operation. 

the  change-speed  and  emergency-brake  levers  on  the  latest  Knox  cars 
is  shown  at  Fig.  375.  The  complete  control  system  of  Mitchell  cars 
is  shown  at  Fig.  376.  The  placing  of  the  hand  levers  on  the  Jackson 
car  and  the  functions  of  the  foot  pedals  are  clearly  depicted  at 
Fig.  377. 

The  instructions  given  for  operating  one  type  of  car  with  selective 
sliding-gear  transmission  applies  just  as  well  to  all  other  forms,  which 
are  controlled  in  practically  the  same  manner  and  which  differ  only  ; 
in  the  arrangement  of  the  slots  in  the  guiding  gate  and  the  location 
and  direction  of  movement  of  the  spark  and  throttle  levers.  Prac- 
tically the  same  units  are  used  in  all  control  systems  of  sliding-gear 


The  Modern  Gasoline  Automobile  631 

cars,  i.  e.,  two  pedals  and  two  hand  levers  are  usually  provided.  One 
of  the  pedals  invariably  releases  the  clutch  while  the  other  applies  the 
service  brake.  One  hand  lever,  always  the  one  nearest  the  operator, 
is  used  to  shift  the  gears,  while  the  one  that  works  on  a  notched  seg- 
ment is  depended  upon  to  apply  the  emergency  brakes. 

General  Driving  Instructions, — The  following  instructions  apply  to 
all  types  of  gasoline  automobiles  and  may  be  followed  to  advantage  by 
all  motorists.  The  gear-shift  lever  should  always  be  placed  in  a  neu- 
tral position  when  the  car  is  stopped,  whether  it  is  left  alone  or  at- 
tended. Gear-shift  levers  should  always  move  easily  and  the  clutch 
pedal  of  all  cars  equipped  with  sliding-gear  transmission  should  be 
fully  depressed  before  attempt  is  made  to  shift  speeds.  The  clutch 
should  always  be  applied  gradually  and  as  slowly  as  possible  because 
too  sudden  or  harsh  engagement  will  produce  stresses  that  will  injure 
the  tires  or  mechanism  of  the  chassis.  Never  allow  the  engine  to  race 
or  run  excessively  fast  when  shifting  gears,  and  it  is  well  not  to  under- 
take to  change  speeds  with  either  motor  or  car  running  at  high  speed. 
When  changing  down,  i.  e.,  from  a  higher  to  a  lower  gear,  allow  the 
car  to  slow  down  until  its  speed  is  about  the  same  as  that  which  will 
be  produced  by  the  lower  gear  ratio  desired  before  the  clutch  is  again 
engaged  after  the  gear  lever  has  been  shifted. 

If  difficulty  is  experienced  in  meshing  the  gears  do  not  try  and 
force  them  in  mesh  but  hold  the  clutch  pedal  out  for  a  few  minutes, 
let  the  car  come  to  almost  a  stop,  apply  the  clutch  quickly,  and  release 
it  at  once  and  the  chances  are  that  the  troublesome  shift  member  will 
have  turned  to  a  position  where  it  will  engage  more  easily.  Some- 
times one  or  more  of  the  gear  teeth  on  the  shift  member  or  the  gear 
with  which  it  engages  may  be  burred  up  on  the  edges  and  will  not 
engage  promptly,  whereas  other  portions  of  the  same  members  will 
have  undamaged  teeth  that  will  easily  slip  into  engagement. 

Always  drive  a  car  slowly  and  cautiously  until  you  are  thoroughly 
familiar  with  the  control  mechanism  and  the  methods  of  stopping  the 
car.  When  driving  up  grades  on  the  higher  ratios,  if  the  motor  shows 
any  tendency  to  labor,  shift  back  into  a  lower  gear  ratio  which  has 
boon  provided  for  that  purpose.  Many  motorists  believe  that  the  best 
••test  of  a  car's  ability  is  to  rush  all  hills,  or  bad  spots  in  roads,  on  the 
direct  drive.  It  should  be  remembered  that  the  lower  speed  ratios 


632  The  Modern  Gasoline  Automobile 

were  provided  for  use  at  all  times  when  employing  the  third  or  fourth 
speeds  might  produce  strains  in  the  motor.  All  unusual  noises  should 
be  investigated  at  once,,  as  these  sounds  usually  presage  more  or  less 
serious  trouble.  A  gasoline  car  should  never  be  driven  with  a  slipping 
clutch,  and  it  is  imperative  that  the  brakes  and  steering  gear  be  fre- 
quently inspected  to  make  sure  that  they  are  in  proper  order. 

One  should  never  attempt  to  drive  cars  at  high  speeds  unless  the 
tire  casings  are  in  perfect  condition  and  the  road  surfaces  good.  In 
driving  on  clay  or  muddy  roads,  or  on  wet  asphalt,  care  must  be  taken 
in  turning  corners  and  the  car  should  be  driven  cautiously  to  avoid 
dangerous  side  slipping  or  skidding.  When  driving  on  unfavorable 
highway  surfaces  always  keep  one  side  of  the  car  on  firm  ground,  if 
possible.  Brakes  should  always  be  carefully  applied,  especially  if  the 
road  surfaces  are  wet.  An  automobile  should  never  be  brought  to  a 
stop  in  mud,  clay  or  sand,  snow  or  slush,  if  it  can  be  avoided.  When- 
ever road  conditions  are  unfavorable  the  smooth  tread  tires  of  the 
driving  wheels  should  always  be  fitted  with  chain-tire  grips  to  insure 
having  adequate  traction. 

All  motorists  should  familiarize  themselves  as  much  as  possible 
with  the  mechanism  of  their  cars  and  should  be  competent  to  make  the 
ordinary  adjustments  and  minor  repairs  before  any  long  trips  are 
attempted.  A  full  equipment  of  tools  and  spare  tires  and  casings 
should  be  carried  at  all  times.  It  is  well  to  remember  that  the  manu- 
facturer of  the  car  has  issued  a  set  of  instructions  for  its  care  and 
maintenance,  and  these  should  be  followed  as  closely  as  possible  be- 
cause intelligent  care  of  any  piece  of  machinery  means  long  life  and 
reliable  service  and  the  automobile  is  no  exception  to  the  rule. 

Suggestions  for  Oiling. — One  of  the  most  important  points  to  be 
observed  in  connection  with  gasoline-automobile  operation  is  that  all 
parts  be  oiled  regularly.     It  is  not  enough  to  apply  lubricant  indis- 
criminately to  the  various  chassis  parts,  but  it  must  be  done  systemati- 
cally and  logically  to  secure  the  best  results  and  insure  the  economical ; 
use  of  lubricant,     The  most  important  parts  are  the  power  plant  and ; 
transmission  system  and  the  engine  is  but  one  point  in  the  car  that 
must  be  properly  oiled  at  all  times  to  obtain  satisfactory  results.    Some 
of  the  running-gear  parts  are  relatively  unimportant,  others  demand 
regular 'inspection  and  oiling. 


The  Modern  Gasoline  Automobile  633 

A  very  comprehensive  oiling  chart  is  presented  at  Fig.  378,  this 
showing  practically  all  of  the  points  that  require  oil  as  well  as  giving 
instructions  regarding  the  character  of  the  lubricant  needed  and  how 
often  it  should  be  applied.  Some  of  the  points  are  governed  by 
special  instructions,  these  being  the  clutch,  transmission  case,  timer, 
and  rear  axle.  The  points  of  the  clutch  which  need  lubricant  vary 
with  the  form  of  clutch  employed.  Multiple-disk  types  which  run  in 
oil  must  be  kept  filled  up  with  the  proper  grade  of  lubricant.  At  the 
other  hand  cone  and  dry-plate  clutches  work  better  without  any  lubri- 
cant between  the  surfaces.  '  When  a  cone  clutch  is  employed  it  is 
sometimes  desirable  to  soften  the  leather  facings  with  a  little  castor  oil 
or  neatsfoot  oil,  if  the  action  is  beginning  to  get  hard.  A  transmission- 
gear  case  which  is  moderately  tight  can  be  filled  with  a  good  grade  of 
steam-engine  cylinder  oil,  and  heavy  grease  should  not  be  used  if  the 
transmission  shafts  run  on  ball  bearings.  A  heavy  cylinder  oil  will 
have  sufficient  viscosity  to  cushion  the  teeth  of  the  gears  against 
shock  and  at  the  same  time  it  will  not  be  too  heavy  to  flow  into  the 
bearings  and  lubricate  them  properly. 

Neither  the  transmission  case  nor  the  differential  case  on  the 
rear  axle  should  be  filled  with  the  heavy  "  Dope "  widely  sold, 
which  may  contain  wood  fiber  or  cork  -particles  to  make  for  more 
silent  operation.  If  gearing  is  noisy  it  is  either  because  it  is  worn 
or  out  of  adjustment,  and  the  use  of  nostrums  and  freak  lubri- 
cants will  not  improve  their  operation.  The  rear-axle  differential 
housing  should  be  filled  with  as  light  mineral  grease  as  it  is  pos- 
sible to  get,  those  having  about  the  consistency  of  vaseline  being  the 
most  desirable  as  lubricants.  Light  oils  should  never  be  used  in 
either  the  transmission-gear  case  or  in  the  rear-axle  housing,  because 
these  will  not  stay  in  place  and  will  not  have  sufficient  body  to  cushion 
the  gear  teeth. 

The  only  other  point  on  the  chart  which  needs  explanation  is 
lubrication  of  the  timer  interior.  This  should  only  be  oiled  when 
it  is  a  roller  contact  form  and  then  a  few  drops  of  dynamo,  magneto, 
or  spindle  oil  applied  to  the  roll  and  the  contact  segments  once  a 
week  is  all  that  is  necessary.  If  the  timer  is  a  form  using  platinum 
contact  points  it  does  not  need  any  lubricant.  Never  use  graphite 
grease  or  any  heavy  oil  in  a  timer  case  because  these  will  not  only 


634  The  Modern  Gasoline  Automobile 

interfere  with  regular  ignition  by  short  circuiting  the  current,  but  they 
will  clog  up  the  tinier  and  prevent  the  roller  establishing  proper  con- 
tact with  the  segments. 

After  a  car  is  oiled  it  is  well  to  go  over  all  the  exposed  joints  with 
a  piece  of  cloth  to  remove  the  accumulations  of  surplus  oil  on  the 
outside  of  the  parts  which  serve  no  useful  purpose  and  which  only  act 
to  attract  and  retain  dust  and  grit.  The  instructions  given  on  the  chart 
can  be  followed  to  advantage  on  all  types  of  gasoline  cars,  though,  of 
course,  the  different  constructions  will  have  to  be  treated  as  the  peculi- 
arities of  design  dictate. 

Winter  Care  of  Automobiles. — While  motoring  throughout  the  en- 
tire year  is  not  unusual,  many  owners  of  cars,  especially  in  those  por- 
tions of  the  country  where  the  winter  climate  is  exceptionally  severe, 
put  up  their  car  for  a  period.  If  the  car  is  to  be  kept  in  service  the  most 
important  thing  to  do  is  to  provide  some  good  antifreezing  compound 
in  order  to  prevent  the  water  in  the  radiator  and  cylinders  from  con- 
gealing. There  is  some  difference  of  opinion  regarding  the  best  solu- 
tion to  use  to  prevent  cracked  water  jackets  and  burst  radiators.  Be- 
fore we  attempt  to  answer  the  questions  often  asked  regarding  the  best 
antifreezing  compound,  it  will  be  well  to  consider  the  requirements  of 
such  compounds.  To  begin  with  it  'should  have  no  deleterious  effects 
on  the  metals  or  rubber  used  in  the  circulating  system.  It  must  be 
easily  dissolved  or  combined  with  water,  should  be  reasonably  cheap, 
and  not  subject  to  waste  by  evaporation  or  be  of  such  character  that 
it  will  deposit  foreign  matter  in  the  pipes.  The  boiling  point  should 
be  higher  than  that  of  water  to  prevent  boiling  away  of  the  solution 
at  comparatively  low  temperature. 

Solutions  of  calcium  chloride  seem  to  be  very  popular  with  motor- 
ists, and  the  writer  will  first  discuss  the  use  of  this  substance.  The 
freezing  point  of  the  solution  depends  upon  the  proportions  of  the 
salt  to  the  water.  An  important  factor  to  be  considered  is  that  if  the 
parts  of  the  circulation  system  are  composed  of  different  metals  there 
is  liable  to  be  a  certain  electrolytic  action  between  the  salt  and  the 
dissimilar  metals  at  the  points  of  juncture,  a  certain  corrosion  taking 
place,  and  the  intensity  of  this  corrosive  effect  is  only  dependent  upon 
the  strength  of  the  solution.  As  calcium  chloride  is  derived  from 
hydrochloric  acid,  which  has  very  strong  effect  on  metals,  and  as  there 


The  Modern  Gasoline  Automobile  635 

may  be  particles  of  free  acid  in  the  solution,  a  certain  undesirable 
corrosive  action  may  take  place. 

In  using  calcium  chloride  when  compounding  an  antifreezing  solu- 
tion care  must  be  taken  that  commercially  pure  salt  is  employed  as  the 
cruder  grades  will  liberate  a  larger  percentage  of  free  acid.  The  mis- 
take should  not  be  made  of  using  chloride  of  lime,  which  has  much  the 
same  appearance,  but  whose  corrosive  action  is  very  great.  Galvan- 
ized iron  tanks  and  cast  aluminum  water  manifolds  and  pump  casings 
prohibit  the  use  of  this  salt  as  its  destructive  action  is  great  on  these 
metals. 

It  is  well  to  test  a  solution  of  calcium  chloride  for  acid  before  plac- 
ing in  the  radiator.  A  piece  of  blue  litmus  paper  may  be  obtained  at 
any  drug  store  and  immersed  in  the  solution.  If  the  paper  turns  red 
it  is  a  sign  that  there  is  acid  present.  Acid  may  be  neutralized  by  the 
addition  of  a  small  quantity  of  slacked  lime. 

The  solutions  may  be  made  in  these  proportions : 

Two  pounds  of  salt  to  the  gallon  of  water  will  freeze  at  eighteen 
degrees  Fahrenheit. 

Three  pounds  of  salt  to  the  gallon  of  water  will  freeze  at  one  and 
five  tenth  degrees  Fahrenheit. 

Four  pounds  of  salt  to  the  gallon  will  freeze  at  seventeen  degrees 
Fahrenheit  below  zero. 

Five  pounds  of  salt  to  the  gallon  will  freeze  at  thirty-nine  degrees 
Fahrenheit  below  zero. 

It  must  be  remembered  that  the  more  salt  to  the  solution,  the 
greater  the  electrolytic  effect  and  the  greater  the  liability  of  the  deposit 
of  salt  crystals,  which  may  obstruct  the  free  flow  of  the  liquid. 

Glycerin  is  usually  considered  quite  favorably,  but  it  has  disad- 
vantages. It  often  contains  free  acid,  though  the  action  on  metals  will 
be  imperceptible  in  average  solutions.  While  it  does  not  attack  metal 
piping  to  any  extent  it  is  sure  destruction  to  rubber  hose  and  should 
not  be  used  in  a  car  in  which  part  of  the  circulation-system  piping  is 
of  rubber.  Glycerin  is  expensive  and  it  is  liable  to  decompose  under 
the  influence  of  heat  and  proportions  added  to  the  water  must  be 
higher  than  that  of  some  other  substances. 

Denatured  alcohol  is  without  doubt  the  best  substance  to  use  as  it 
does  not  have  any  destructive  action  on  the  metals  or  rubber  hose, 


636  The  Modern  Gasoline  Automobile 

will  not  form  deposits  of  foreign  matter,  and  has  no  electrolytic  effect. 
A  solution  of  sixty  per  cent  water  and  forty  per  cent  alcohol  will 
stand  twenty-five  degrees  below  zero  without  freezing.  The  chief  dis- 
advantage to  its  use  is  that  it  evaporates  easily  and  its  boiling  point 
is  quite  low.  Alcohol  volatilizes  more  rapidly  than  water  and  the 
solution  is  liable  to  become  too  light  as  proportion  of  alcohol  to  water 
is  concerned.  The  percentages  required  are  shown  in  the  following: 

Water  ninety-five  per  cent,  alcohol  five  per  cent,  freeze  at  twenty- 
five  degrees  Fahrenheit;  water  eighty-five  per  cent,  alcohol  fifteen 
per  cent,  freeze  at  eleven  degrees  Fahrenheit;  water  eighty  per  cent, 
alcohol  twenty  per  cent,  freeze  at  five  degrees  Fahrenheit;  water 
seventy  per  cent,  alcohol  thirty  per  cent,  freeze  at  nine  degrees  Fahren- 
heit below  zero ;  water  sixty- five  per  cent,  alcohol  thirty-five  per  cent, 
freeze  at  sixteen  degrees  Fahrenheit  below  zero. 

Various  mixtures  have  been  tried  of  alcohol,  glycerin,  and  water, 
and  good  results  obtained.  The  addition  of  glycerin  to  a  water- 
alcohol  solution  reduces  liability  of  evaporation  to  a  large  extent,  and 
when  glycerin  is  used  in  such  proportions  it  is  not  liable  to  damage 
the  rubber  hose. 

The  proportions  recommended  are  a  solution  of  half  glycerin, 
half  alcohol  to  water.  The  glycerin  in  such  a  solution  will  remain 
practically  the  same,  not  being  subject  to  evaporation,  and  water  and 
alcohol  must  be  supplied  if  amount  of  solution  in  radiator  is  not 
enough.  The  freezing  temperatures  of  such  solutions  of  varying  pro- 
portions are  as  follows :  Water  eighty-five  per  cent,  alcohol  and  glycer- 
in fifteen  per  cent,  freeze  at  twenty  degrees  Fahrenheit;  water 
seventy-five  per  cent,  alcohol  and  glycerin  twenty-five  per  cent, 
freeze  at  eight  degrees  Fahrenheit;  water  seventy  per  cent,  alcohol 
and  glycerin  thirty  per  cent,  freeze  at  five  degrees  Fahrenheit  below 
zero ;  water  sixty  per  cent,  alcohol  and  glycerin  forty  per  cent,  freeze 
at  twenty-three  degrees  Fahrenheit  below  zero. 

The  proper  proportions  to  be  used  must  of  course  be  governed  by 
conditions  of  locality,  but  it  is  better  to  be  safe  than  sorry,  and  make 
the  solutions  strong  enough  for  the  extreme  that  may  be  expected. 

Oils  of  various  kinds  are  often  used  exclusively,  as  it  is  obvious 
that  oil  and  water  would  not  form  a  very  good  mixture.  They  are 
of  the  character  that  is  often  used  to  lubricate  ice-making  machinery, 


The  Modern  Gasoline  Automobile  637 

and  are  made  especially  to  withstand  low  temperatures.  The  oil  will 
not  absorb  heat  as  readily  as  water,  and  should  only  be  used  where 
exceptionally  good  methods  of  cooling  are  provided,  such  as  a  large 
radiator,  all  metal  piping  and  a  very  positive  pump.  This  oil  will 
attack  rubber  hose  and  gaskets,  however.  It  would  seem  to  the  writer, 
from  actual  experience,  that  wood-alcohol  solutions  were  preferable  to 
others  as  combining  the  greatest  number  of  the  requirements  of  a 
practical  antifreezing  compound. 

After  due  care  has  been  taken  with  the  cooling  system  to  prevent 
freezing,  the  next  point  to  observe  is  the  lubrication  of  the  motor. 
This  will  depend  on  the  oil  system  used  and  the  grades  of  oil  which 
are  normally  employed.  As  a  general  rule  it  is  well  to  use  a  lighter 
grade  in  the  winter  than  that  utilized  during  warmer  weather.  If  the 
clutch  is  a  multiple-disk  member  it  should  be  filled  with  light  oil  of 
as  high  cold  test  as  it  is  possible  to  obtain.  If  sight-feed  glasses  and 
exposed  tubing  forms  part  of  the  lubricating  system  or  the  oil  tank  or 
mechanical  lubricator  is  carried  in  an  exposed  position  it  should  be  re- 
membered that  this  part  should  be  inspected  frequently  to  make  sure 
that  the  oiling  system  is  functioning  properly. 

If  an  acetylene-lighting  system  utilizing  a  gas  generator  is  fitted 
it  is  necessary  that  the  water  used  in  the  water  tank  or  the  water 
jacket  provided  on  some  generators  be  drained  off  and  replaced  with 
a  solution  of  denatured  alcohol  and  water  of  the  proper  consistency 
for  the  degree  of  temperature  liable  to  be  met  with.  During  cold 
weather  a  certain  amount  of  difficulty  is  always  experienced  in  start- 
ing the  car,  especially  when  one  considers  the  low  grade  of  gasoline 
used  at  the  present  time. 

If  the  motor  is  provided  with  compression  relief  or  priming  cocks, 
a  small  hand  oil  can  should  be  filled  with  gasoline  and  ether  mixture  of 
proportions  about  half  and  half  and  kept  tightly  corked  to  prevent 
evaporation  of  the  volatile  liquids.  On  a  cold  morning  when  the 
motor  is  hard  to  start,  this  liquid  may  be  injected  into  the  cylinders, 
through  the  priming  cock  or  by  removing  the  spark  plugs  if  relief 
cocks  are  not  provided  and  the  motor  will  be  started  without  difficulty. 
If  no  priming  can  is  available  one  of  the  methods  of  securing  gasoline 
shown  at  Fig.  379  for  priming  purposes  may  be  used  to  advantage. 
At  A  one  of  the  tire  valve  caps  is  utilized  as  a  cup  to  remove  a  certain 


638 


The  Modern  Gasoline  Automobile 


portion  of  gasoline  from  the  tank.  It  is  utilized  by  tying  a  piece  of 
cord  or  wire  to  the  end  and  then  dropping  it  into  the  gasoline  tank 
through  the  filler  opening.  One  of  these  caps  will  hold  enough  gaso- 
line to  start  the  ordinary  four-cylinder  motor.  Another  method  of 
accomplishing  the  same  result  is  shown  at  B.  In  this  a  piece  of 


Tank 


Waste 


Fig.  379. — Two  Methods  of  Obtaining  Gasoline  from  Container  to  Prime  Cylin- 
ders and  Facilitate  Motor  Starting  in  Cold  Weather. 

waste  is  tied  into  a  ball  and  dropped  into  the  gasoline  tank.  When 
removed  it  is  saturated  with  fuel  and  enough  gasoline  may  be  squeezed 
from  the  waste  into  the  priming  cocks  to  prime  the  motor.  If  an  oil 
squirt  gun  forms  part  of  the  tool  equipment,  this  may  be  used  to  draw 
gasoline  from  the  tank  without  difficulty. 

In  extreme  cold  weather  many  motorists  disconnect  the  fan  belt 
in  order  that  the  air  draught  through  the  radiator  will  not  cool  the 
water  to  such  a  point  that  the  engine  will  not  run  efficiently.  Other 
motorists  provide  some  form  of  a  lined  leather  shield  for  the  front 
of  the  radiator,,  as  shown  at  Fig.  380.  At  A  the  shield  is  shown  partly 
opened  so  that  a  large  area  of  the  radiator  is  exposed  to  the  air.  At  B 
the  openings  in  the  shield  have  been  closed  by  the  shutter-like  closure 
and  the  radiator  is  protected  in  such  a  way  that  the  water  will  be  kept 
warm  if  a  stop  of  any  consequence  is  made. 

Spot-Removing  Preparations. — A  point  that  worries  many  motor* 
ists,  especially  those  of  the  gentler  sex?  is  the  methods  of  removing 


The  Modern  Gasoline  Automobile 


639 


oil  spots  which  frequently  are  present  upon  the  clothing  of  motorists. 
The  following  rules  will  be  found  valuable  in  this  connection : 

Most  frequent  among' the  various  kinds  of  spots  are  those  due  to 
oil  or  grease.  Materials  in  delicate  colors  require  a  special  treatment 
so  their  shade  will  not  be  changed.  If  a  grease  spot  is  to  be  re- 
moved, the  main  portion  of  the  grease  is  first  carefully  scraped  off  by 
means  of  a  knife  blade.  A  plaster  of  Fuller's  earth,  prepared  by  dilut- 
ing the  earth  with  a  little  water,  is  applied  to  the  surface  affected. 
This  remains  in  place  for  several  minutes,  and  is  then  scraped  off. 
Any  particles  of  Fuller's  earth  remaining  on  the  cloth  can  be  washed 
off  with  water.  By  lightly  ironing  out  the  affected  portion  of  the 
garment  it  will  be  completely  renovated. 

In  no  case  should  a  solvent  (benzene  or  gasoline)  be  used  for  re- 
moving spots  from  materials  dyed  in  light  shades,  as  there  is  danger 


Fig.  380. — Special  Cover  to  Protect  Radiator  During  Cold  Weather  and  Prevent 
Freezing  Cooling  Water.  A— Slots  Open  for  Air  Passage  while  Car  is 
Used.  B— Radiator  Completely  Protected  when  Engine  is  Stopped.  Cover 
Retains  Heat  and  Makes  for  Easy  Restarting. 

that  the  dye  will  be  dissolved  with  the  grease.  Cotton  and  linen  gar- 
ments, whether  white  or  d}^ed,  can  be  restored  by  local  treatment  with 
soap.  Materials  that  are  not  dyed  and  broadcloth  may  be  easily 
cleaned  by  means  of  benzol,  gasoline  or  alcohol-benzol  mixtures,  the 
latter  being  the  best  solvent. 

Material  of  light  weight  is  stretched  between  the  hands  and  the 


640  The  Modern  Gasoline  Automobile 

solvent  is  poured  on  it  drop  by  drop  until  the  cloth  is  penetrated. 
The  degreasing  process  is  completed  by  pressing  the  moist  portion  be- 
tween two  pieces  of  clean  linen.  If  the  material  is  heavy — such  as 
broadcloth — the  spot  is  rubbed  repeatedly  with  a  rag  of  linen  soaked 
with  one  of  the  solvents  mentioned  above,  until  the  material  is 
moistened  all  through,  and  care  must  be  taken  to  discard  the  rag  as 
soon  as  it  becomes  dirty,  and  use  a  clean  one. 

Kerosene  spots,  which  are  easily  formed,  should  first  be  treated 
with  a  slight  coating  of  vegetable  oil  (lubricating  oil ;  or,  better,  olive 
oil),  so  as  to  absorb  the  kerosene,  and  then  treated  with  the  Fuller's 
earth  plaster,  which  absorbs  the  whole  quite  rapidly. 

Authorities  recommend  a  number  of  liquid  compositions  for  re- 
moving grease  spots  from  cloths  which  are  not  delicate.  One  of  the 
simplest  of  these  consists  of 

Wood  alcohol 2  parts 

Alcoholic  essence  of  soap 2  parts 

Ammonia 4  parts 

Turpentine 4  parts 

The  alcoholic  essence  of  soap  is  prepared  by  dissolving  some  white 
Marseilles  soap  in  sixteen  times  the  amount  of  ninety  degrees  alcohol, 
and  adding  ten  parts  of  water.  The  white  Marseilles  soap  is  probably 
substantially  the  same  as  Ivory  soap.  Any  druggist  will  undertake  to 
prepare  this  essence.  It  is  sufficient  to  apply  it  moderately  with  a 
linen  rag. 

Finally,  on  a  road  only  recently  tarred  the  motorist's  clothes  may 
be  spattered  with  tar  and  their  treatment  is  a  rather  delicate  matter. 
If  washable  garments  or  fast-color  materials  are  spotted  by  this  ma- 
terial, one  may,  after  having  removed  the  greater  portion  of  the  tar 
by  scraping,  pour  either  benzol  or  gasoline  drop  by  drop  on  the  back 
side  of  the  material,  so  the  solvent  will  run  through  the  spotted  part. 
If  the  material  is  light  colored  it  may  be  nearly  completely  cleaned  1  > y 
using  a  rag  soaked  in  gasoline,  and  taking  care  to  touch  only  the  spot. 
This  latter  treatment  calls  for  considerable  skill,  but  with  patience  one 
is  usually  successful. 


CHAPTER    XIII 

Practical  Hints  to  Assist  in  Locating  Power-Plant  Troubles — Systematic 
Detection  of  Conditions  to  which  Imperfect  Operation  Can  Be  Ascribed 
Faults  in  the  Ignition  System — Derangements  of  the  Carburetion  Group 
and  Their  Symptoms — Cooling  and  Lubrication  Group  Troubles. 

OXE  versed  in  motor-car  construction  and  repair  processes  does 
not  have  any  difficulty  in  tracing  the  common  motor  troubles  to  their 
source  and  the  expert  readily  recognizes  the  symptoms  which  denote 
faulty  action  of  any  of  the  power-plant  components.  The  average 
motorist,  who  has  but  little  mechanical  experience,  is  apt  to  become 
hopelessly  confused  when  even  the  simpler  derangements,  liable  to  oc- 
cur at  any  time,  materialize.  One  who  is  not  thoroughly  familiar  with 
motor-car  construction  will  seldom  locate  troubles  by  haphazard  ex- 
perimenting and  it  is  only  by  a  systematic  search  that  the  cause  can 
be  discovered  and  the  defects  eliminated.  In  this  chapter  the  writer 
proposes  to  outline  some  of  the  most  common  power-plant  troubles 
and  to  give  sufficient  advice  to  enable  those  who  are  not  thoroughly 
informed  to  locate  them  by  a  logical  process  of  elimination. 

The  internal-combustion  motor,  which  is  the  power  plant  of  all 
gasoline  automobiles,  is  composed  of  a  number  of  distinct  groups, 
which  in  turn  include  distinct  components.  These  various  appliances 
are  so  closely  related  to  each  other  that  defective  action  of  any  one 
may  interrupt  the  operation  of  the  entire  power  plant.  Some  of  the 
auxiliary  groups  are  more  necessary  than  others  and  the  power  plant 
will  continue  to  operate  for  a  time  even  after  the  failure  of  some 
important  parts  of  some  of  the  auxiliary  groups.  The  gasoline  engine 
in  itself  is  a  complete  mechanism,  but  it  is  evident  that  it  cannot  de- 
liver any  power  without  some  means  of  supplying  gas  to  the  cylinders 
and  igniting  the  compressed  gas  charge  after  it  has  been  compressed 
in  the  cylinders.  From  this  it  is  patent  that  the.  ignition  and  car- 
buretion  systems  are  just  as  essential  parts  of  the  power  plant  as  the 

641 


642  The  Modern  Gasoline  Automobile 

piston,  connecting  rod,  or  cylinder  of  the  motor.  The  failure  of 
either  the  carburetor  or  igniting  means  to  function  properly  will  be 
immediately  apparent  by  faulty  action  of  the  power  plant. 

To  insure  that  the  motor  will  continue  to  operate  it  is  necessary  to 
keep  it  from  overheating  by  some  form  of  cooling  system  and  to  supply 
oil  to  the  moving  parts  to  reduce  friction.  The  cooling  and  lubrica- 
tion groups  are  not  so  important  as  carburetion  and  ignition,  as  the 
engine  would  run  for  a  limited  period  of  time  even  should  the  cooling 
system  fail  or  the  oil  supply  cease.  It  would  only  be  a  few  moments, 
however,  before  the  engine  would  overheat  if  the  cooling  system  was 
at  fault,  and  the  parts  seize  if  the  lubricating  system  should  fail. 
Any  derangement  in  the  carburetor  or  ignition  mechanism  would  man- 
ifest itself  at  once  because  the  engine  operation  would  be  affected,  but 
a  defect  in  the  cooling  or  oiling  system  would  not  be  noticed  so  readily. 

The  careful  motorist  will  always  inspect  the  motor  mechanism 
before  starting  on  a  trip  of  any  consequence,  and  if  inspection  is  care- 
fully carried  out  and  loose  parts  tightened  it  is  seldom  that  irregular 
operation  will  be  found  due  to  actual  breakage  of  any  of  the  compo- 
nents of  the  mechanism.  Deterioration  due  to  natural  causes  matures 
slowly,  and  sufficient  warning  is  always  given  when  parts  begin  to 
wear  so  satisfactory  repairs  may  be  promptly  made  before  serious  de- 
rangement or  failure  is  manifested. 

A  Typical  Engine  Stoppage  Analyzed. — Before  describing  the  points 
that  may  fail  in  the  various  auxiliary  systems  it  will  be  well  to  assume 
a  typical  case  of  engine  failure  and  show  the  process  of  locating  the 
trouble  in  a  systematic  manner  by  indicating  the  various  steps  which 
are  in  logical  order  and  which  could  reasonably  be  followed.  In  any 
case  of  engine  failure  the  ignition  system,  motor  compression,  and 
carburetor  should  be  tested  first.  If  the  ignition  system  is  function- 
ing properly  one  should  determine  the  amount  of  compression  in  all 
cylinders  and  if  this  is  satisfactory  the  carbureting  group  should  be 
tested.  If  the  ignition  system  is  working  properly  and  there  is  a 
decided  resistance  in  the  cylinders  when  the  starting  handle  is  turned, 
proving  that  there  is  good  compression,  one  may  suspect  the  carburetor. 

If  the  ca'rburetor  appears  to  be  in  good  condition,  the  trouble 
may  be  .caused  by  the  ignition  being  out  of  time,  which  condition  is 
possible  when  the  timer  is7  attached  to  the  cam  shaft  by  a  set  screw 


The  Modern  Gasoline  Automobile  643 

or  the  magneto  timing  gear  to  the  armature  shaft  by  a  taper 
and  nut  retention  instead  of  the  more  positive  key  or  taper-pin 
fastening.  It  is  possible  that  the  inlet  manifold  may  be  broken  or 
perforated,  that  the  exhaust  valve  is  stuck  on  its  seat  because  of  a 
broken  or  bent  stem,  broken  or  loose  cam,  or  failure  of  the  cam-shaft 
drive  because  the  teeth  are  stripped  from  the  engine  shaft  or  cam-shaft 
gears ;  or  because  the  key  or  other  fastening  on  either  gear  has  failed, 
allowing  that  member  to  turn  independently  of  the  shaft  to  which  it 
normally  is  attached.  The  gasoline  feed  pipe  may  be  clogged  or  broken, 
the  fuel  supply  may  be  depleted,  or  the  shut-off  cock  in  the  gasoline 
line  may  have  jarred  closed.  The  gasoline  filter  may  be  filled  with 
dirt  or  water  which  prevents  passage  of  the  fuel. 

The  defects  outlined  above,  except  the  failure  of  the  gasoline  sup- 
ply, are  very  rare,  and  if  the  container  is  found  to  contain  fuel  and 
the  pipe  line  to  be  clear  to  the  carburetor,  it  is  safe  to  assume  the 
vaporizing  device  is  at  fault.  If  fuel  continually  runs  out  of  the 
mixing  chamber  the  carburetor  is  said  to  be  flooded.  This  condition 
results  from  failure  of  the  shut-off  needle  to  seat  properly  or  from  a 
punctured  hollow  metal  float  or  a  gasoline-soaked  cork  float.  It  is 
possible  that  not  enough  gasoline  is  present  in  the  float  chamber. 
If  the  passage  controlled  by  the  float-needle  valve  is  clogged  or  if  the 
float  was  badly  out  of  adjustment,  this  contingency  would  be  probable. 
When  the  carburetor  is  examined,  if  the  gasoline  level  appears  to  be 
at  the  proper  height,  one  may  suspect  that  a  particle  of  lint,  or  dust, 
or  fine  scale,  or  rust  from  the  gasoline  tank  has  clogged  the  bore  of  the 
jet  in  the  mixing  chamber. 

If  the  ignition  system  and  carburetor  appear  to  be  in  good  working 
order,  and  the  hand  crank  shows  that  there  is  no  compression  in  one 
or  more  of  the  cylinders,  it  means  some  defect  in  the  valve  system.  If 
the  engine  is  a  multiple-cylinder  type  and  one  finds  poor  compression 
in  all  of  the  cylinders  it  may  be  due  to  the  rare  defect  of  improper 
valve  timing.  This  may  be  caused  by  a  gear  having  altered  its  position 
on  the  cam  shaft  or  crank  shaft,  because  of  a  sheared  key  or  pin  having 
permitted  the  gear  to  turn  about  a  half  of  a  revolution  and  then 
having  caught  and  held  the  gear  in  place  by  a  broken  or  jagged  end 
so  that  cam  shaft  would  turn,  but  the  valves  open  at  the  wrong  time. 
If  but  one  of  the  cylinders  is  at  fault  and  the  rest  appear  to  have 


644  The  Modern  Gasoline  Automobile 

good  compression  the  trouble  may  be  due  to  a  defective  condition 
either  inside  or  outside  of  that  cylinder.  The  external  parts  may 
be  inspected  easily,  so  the  following  should  be  looked  for:  a  broken 
valve,  a  warped  valve  head,  broken  valve  springs,  sticking  or  bent 
valve  stems,  dirt  under  valve  seat,  leak  at  valve-chamber  cap  or  spark- 
plug gasket.  Defective  priming  cock,  cracked  cylinder  head  (rarely 
occurs),  leak  through  cracked  spark-plug  insulation,  valve  plunger 
stuck  in  the  guide,  lack  of  clearance  between  valve-stem  end  and  top 
of  plunger  caused  by  loose  adjusting  screw  which  has  worked  up  and 
kept  the  valve  from  seating.  The  faulty  compression  may  be  due  to 
defects  inside  the  motor.  The  piston  head  may  be  cracked  (rarely 
occurs),  piston  rings  may  be  broken,  the  slots  in  the  piston  rings 
may  be  in  line,  the  rings  may  have  lost  their  elasticity  or  have  become 
gummed  in  the  grooves  of  the  piston,  or  the  piston  and  cylinder  walls 
may  be  badly  scored  by  a  loose  wrist  pin  or  by  defective  lubrication. 
If  the  motor  is  a  type  with  a  separate  head  it  is  possible  the  gasket 
or  packing  between  the  cylinder  and  combustion  chamber  may  leak, 
either  admitting  water  to  the  cylinder  or  allowing  compression  to 
escape. 

Conditions  That  Cause  Failure  of  Ignition  System. — If  the  first 
test  of  the  motor  had  showed  that  the  compression  was  as  it  should 
be  and  that  there  were  no  serious  mechanical  defects  and  there  was 
plenty  of  gasoline  at  the  carburetor,  this  would  have  demonstrated 
that  the  ignition  s}^stem  was  not  functioning  property.  If  a  battery 
is  employed  to  supply  current  the  first  step  is  to  take  the  spark  plugs 
out  of^  the  cylinders  and  test  the  system  by  turning  over  the  engine 
by  hand.  If  there  is  no  spark  in  any  of  the  plugs',  this  may  be  con- 
sidered a  positive  indication  that  there  is  a  broken  main  current  lead 
from  the  battery,  a  defective  ground  connection,  a  loose  battery  ter- 
minal, or  a  broken  connector.  If  none  of  these  conditions  are  present, 
it  is  safe  to  say  that  the  battery  is  no  longer  capable  of  delivering 
current.  If  there  is  no  spark  at  the  plugs,  but  the  spark-coil  vibrator 
functions  properly,  this  shows  that  the  primary  wiring  is  as  it  should 
be  and  that  the  fault  must  be  looked  for  in  either  the  wires  com- 
prising the  secondary  circuit,  or  at  the  plugs. 

The  spark  plugs  may  be  short  circuited  by  cracked  insulation  or 
carbon  and  oil  deposits  around  the  electrode.  The  secondary  wires 


The  Modern  Gasoline  Automobile  645 

may  be  broken  or  have  defective  insulation  which  permits  the  current 
to  ground  to  some  metal  part  of  the  frame  or  motor.  The  battery 
strength  should  be  tested  with  volt  or  ampere  meter  to  determine  if 
the  voltage  and  amperage  are  sufficient.  Storage-battery  capacity  is 
usually  gauged  by  measuring  the  voltage  while  dry  cells  are  judged  by 
their  amperage.  A  storage  battery  should  show  at  least  two  volts 
per  cell,  while  dry  batteries  that  indicate  less  than  seven  amperes  per 
cell  are  not  considered  reliable  or  satisfactory  for  ignition  service. 
If  there  is  no  vibration  at  the  coil  trembler  or  vibrator  the  trouble 
may  be  due  to  weak  current  source,  broken  timer  wires,  or  defective 
connections  at  the  vibrator  or  commutator  contact  points.  The  elec- 
trodes of  the  spark  plug  may  be  too  far  apart  to  permit  a  spark  to 
overcome  the  resistance  of  the  compressed  gas,  even  if  a  spark  jumps 
the  air  space,  when  the  plug  is  laid  on  the  cylinder. 

If  a  magneto  is  fitted  and  a  spark  is  obtained  between  the  points 
of  the  plug  and  that  device  or  the  wire  leading  to  it  from  the  magneto 
is  in  proper  condition,  the  trouble  is  probably  caused  by  the  magneto 
being  out  of  time.  This  may  result  if  the  driving  gear  is  loose  on 
the  armature  shaft  or  crank  shaft,  and  is  a  rare  occurrence.  If  no 
spark  is  produced  at  the  plugs  the  secondary  wire  may  be  broken,  the 
ground  wire  may  make  contact  with  some  metallic  portion  of  the 
chassis  before  it  reaches  the  switch,  the  carbon  collecting  brushes  may 
be  broken  or  not  making  contact,  the  contact  points  of  the  make-and- 
break  device  may  be  out  of  adjustment,  the  wiring  may  be  attached  to 
wrong  terminals,  the  distributor  filled  with  metallic  particles,  carbon, 
dust  or  oil  accumulations,  the  distributor  contacts  may  not  be  making 
proper  connection  because  of  wear  and  there  may  be  a  more  serious 
derangement,  such  as  a  burned  out  secondary  winding  or  a  punctured 
condenser. 

If  the  motor  runs  intermittently,  i.  e.,  starts  and  runs  only  a  few 
revolutions,  aside  from  the  conditions  previously  outlined,  defective 
operation  may  be  due  to  seizing  between  parts  because  of  insufficient 
oil  or  deficient  cooling,  too  much  oil  in  the  crank  case  which  fouls 
the  cylinder  after  the  crank  shaft  has  revolved  a  few  turns,  and  de- 
rangements in  the  ignition  or  carburetion  systems  that  may  be  easily 
remedied.  There  are  a  number  of  defective  conditions  which  may 
exist  in  the  ignition  group,  that  will  result  in  "  skipping  "  or  irregular 


646  The  Modern  Gasoline  Automobile 

operation,,  and  the  following  is  the  logical  order  in  which  the  various 
points  should  be  inspected ;  the  parts  which  demand  inspection  of tenest 
are  considered  first:  weak  source  of  current  due  to  worn  out  dry  cells 
or  discharged  storage  batteries;  weak  magnets  in  magneto,,  or  de- 
fective contacts  at  magneto;  dirt  in  magneto  distributor  or  poor  con- 
tact at  collecting  brushes.  Dirty  or  cracked  insulator  at  spark  plug 
will  cause  short  circuit  and  can  only  be  detected  by  careful  exami- 
nation. The  following  points  should  also  be  checked  over  when  the 
plug  is  inspected :  Excessive  space  between  electrodes,  points  too  close 
together,  loose  central  electrodes,  or  loose  point  on  plug  body,  soot 
or  oil  particles  between  electrodes,  or  on  the  surface  of  the  insulator. 

When  testing  a  dry  battery,  the  terminals  should  be  gone  over 
carefully  to  make  sure  that  all  terminal  nuts  are  tight  and  that  there 
are  no  loose  or  broken  cell  connectors.  The  wiring  at  the  coil,  timer, 
and  switch  should  be  inspected  to  see  that  all  connections  are  tight 
and  that  the  insulation  is  not  chafed  or  cracked.  Defective  insulation 
will  allow  leakage  of  current,  while  loose  connections  make  for  irreg- 
ular operation.  In  testing  a  storage  battery  care  should  be  taken  to 
remove  all  the  verdigris  or  sulphate  from  the  terminals  before  at- 
taching the  testing  wires.  If  a  magneto  is  used  there  may  be  a  short 
circuit  in  the  ground  wire  or  a  poor  connection  at  either  switch  lever  or 
switch  key. 

The  timer  or  distributor  used  with  a  battery-ignition  system  may 
be  dirty  and  if  the  device  wabbles  or  has  loose  bearings,  the  primary 
contact  will  be  very  poor.  The  insulating  ring  at  the  timer  or  dis- 
tributor, or  the  fiber  or  hard-rubber  bushings  at  magneto  or  timer 
may  allow  loss  of  current  if  they  are  cracked.  If  the  ignition  system 
employs  low-tension  sparking  plates  the  igniter  should  be  removed  and 
examined  with  particular  reference  to  the  sparking  or  contact  points 
which  should  be  clean  and  free  from  pits  or  irregular  projections. 
The  bushing  which  insulates  the  fixed  contact  or  anvil  from  the  plate 
should  be  clean  and  free  from  oil  or  cracks.  Wear  in  the  operating 
mechanism  of  the  igniter  will  cause  irregular  operation.  A  poor 
ground  contact  at  a  commutator  of  the  high-tension  system  will  cause 
irregular  ignition. 

If  a  vibrator  coil  is  employed  the  trembler  platinum  contact  points 
should  be  examined  for  pits  or  carbonized  particles  that  would  in- 


The  Modern  Gasoline  Automobile  647 

terfere  with  good  contact.  If  defective,  they  should  be  thoroughly 
cleaned  and  the  surfaces  of  the  platinum  point  on  both  vibrator  spring 
and  adjusting  screw  should  be  filed  smooth  to  insure  positive  contact. 
The  tension  of  the  vibrator  spring  should  not  be  too  light  or  too 
heavy  and  the  vibrator  should  work  rapidly  enough  to  make  a  sharp, 
buzzing  sound  when  contact  is  established  at  the  timer.  The  adjust- 
ing screw  should  be  tight  in  the  vibrator  bridge  and  when  proper 
spring  tension  is  obtained  the  regulating  screw  should  be  locked  firmly 
to  prevent  movement. 

If  the  vibrator  operates  satisfactorily,  but  there  is  a  brilliant  spark 
between  the  vibrator  points  and  a  poor  spark  at  the  spark  plug,  one 
may  assume  that  the  coil  condenser  is  punctured.  Short  circuits  in 
the  condenser  or  internal  wiring  of  induction  coils  or  magnetos,  which 
are  fortunately  not  common,  can  seldom  be  remedied  except  at  the 
factory  where  these  devices  were  made.  If  an  engine  stops  suddenly 
and  the 'defect  is  in  the  ignition  system  the  trouble  is  usually  never 
more  serious  than  a  broken  or  loose  wire.  This  may  be  easily  lo- 
cated by  inspecting  the  wiring  at  the  terminals.  Irregular  operation 
or  misfiring  is  harder  to  locate  because  the  trouble  can  only  be  found 
after  the  many  possible  defective  conditions  have  been  checked  over, 
one  by  one. 

Common  Defects  in  Fuel  Systems. — Defective  carburetion  often 
causes  misfiring  or  irregular  operation.  The  common  derangement  of 
the  components  of  the  fuel  system  that  are  common  enough  to  Warrant 
suspicion  and  the  best  methods  for  their  location  follows :  First,  dis- 
connect the  feed  pipe  from  the  curburetor  and  see  if  the  gasoline 
flows  freely  from  the  tank.  If  the  stream  coming  out  of  the  pipe  is  not 
the  full  size  of  the  orifice  it  is  an  indication  that  the  pipe  is  clogged 
with  dirt  or  that  there  is  an  accumulation  of  rust,  scale,  or  lint  in  the 
strainer  screens  of  the  filter.  It  is  also  possible  that  the  fuel  shut-off 
valve  may  be  wholly  or  partly  closed.  If  the  gasoline  flows  by  gravity 
the  liquid  may  be  air  bound  in  the  tank,  while  if  a  pressure-feed  sys- 
tem is  utilized  the  tank  may  leak  so  that  it  does  not  retain  pressure; 
the  check  valve  retaining  the  pressure  may  be  defective  or  the  pipe 
conveying  the  air  or  gas  under  pressure  to  the  tank  may  be  clogged. 

If  the  gasoline  flows  from  the  pipe  in  a  steady  stream  the  carbur- 
etor demands  examination.  There  may  be  dirt  or  water  in  the  float 


648  The  Modern  Gasoline  Automobile 

chamber,  which  will  constrict  the  passage  between  the  float  chamber 
and  the  spray  nozzle,  or  a  particle  of  foreign  matter  may  have  entered 
the  nozzle  and  stopped  up  the  fine  holes  therein.  The  float  may  bind 
on  its  guide,  the  needle  valve  regulating  the  gasoline-inlet  opening  in 
bowl  may  stick  to  its  seat.  Any  of  the  conditions  mentioned  would 
cut  down  the  gasoline  supply  and  the  engine  would  not  receive  suffi- 
cient quantities  of  gas.  The  air-valve  spring  may  be  weak  or  the  air 
valve  broken.  The  gasoline-adjusting  needle  may  be  loose  and  jar 
out  of  adjustment,  or  the  air- valve  spring-adjusting  nuts  may  be  such 
a  poor  fit  on  the  stem  that  adjustments  will  not  be  retained.  Air  may 
leak  in  through  the  manifold,  due  to  a  porous  casting,  or  leaky  joints 
in  a  built  up  form  and  dilute  the  mixture.  The  air-intake  dust  screen 
may  be  so  clogged  with  dirt  and  lint  that  not  enough  air  will  pass 
through  the  mesh.  Water  or  sediment  in  the  gasoline  will  cause  mis- 
firing because  the  fuel  feed  varies  'when  the  water  or  dirt  constricts 
the  standpipe  bore. 

It  is  possible  that  the  carburetor  may  be  out  of  adjustment.  If 
clouds  of  black  smoke  are  emitted  at  the  exhaust  pipe  it  is  positive 
indication  that  too  much  gasoline  is  being  supplied  the  mixture  and 
the  supply  should  be  cut  down  by  screwing  in  the  needle  valve  on 
types  where  this  method  of  regulation  is  provided,  and  by  making  sure 
that  the  fuel  level  is  at  the  proper  height  in  those  forms  where  the 
spray  nozzle  has  no  means  of  adjustment.  If  the  mixture  contains 
too  much  air  there  will  be  a  pronounced  popping  back  in  the  carburetor. 
This  may  be  overcome  by  screwing  in  the  air-valve  adjustment  so  the 
spring  tension  is  increased  or  by  slightly  opening  up  the  gasoline- 
supply  regulation  needle.  When  a  carburetor  is  properly  adjusted 
and  the  mixture  delivered  the  cylinder  burns  properly,  the  exhaust 
gas  will  be  clean  and  free  from  the  objectionable  odor  present  when 
gasoline  is  burned  in  excess. 

If  a  muffler  cut-out  is  provided  the  character  of  combustion  may 
be  judged  by  the  color  of  the  flame  which  issues  from  it  when  the 
engine  is  running  with  an  open  throttle  after  nightfall.  If  the 
flame  is  red,  it  indicates  too  much  gasoline.  If -yellowish,  it  shows 
an  excess  of  air,  while  a  properly  proportioned  mixture  will  be  evi- 
denced by^a  pronounced  blue  flame,  such  as  given  by  a  gas-stove 
burner. 


The  Modern  Gasoline  Automobile  649 

Defects  in  Oiling  Systems. — While  troubles  existing  in  the  ignition 
or  carburetion  groups  are  usually  denoted  by  imperfect  operation  of 
the  motor,  such  as  lost  power,  and  misfiring,  derangements  of  the 
lubrication  or  cooling  systems  are  usually  evident  by  overheating,  dim- 
inution in  engine  capacity,  or  noisy  operation.  Overheating  may  be 
caused  by  poor  carburetion  as  much  as  by  deficient  cooling  or  insuffi- 
cient oiling.  When  the  oiling  group  is  not  functioning  as  it  should 
the  friction  between  the  motor  parts  produces  heat.  If  the  cooling 
system  is  in  proper  condition,  as  will  be  evidenced  by  the  condition  of 
the  water  in  the  radiator,  and  the  carburetion  group  appears  to  be  in 
good  condition,  the  overheating  is  probably  caused  by  some  defect  in 
the  oiling  system. 

The  conditions  that  most  commonly  result  in  poor  lubrication  are : 
Insufficient  oil  in  the  engine  crank  case  or  sump,  broken  or  clogged 
oil  pipes,  screen  at  filter  filled  with  lint  or  dirt,  broken  oil  pump,  or 
defective  oil-pump  drive.  The  supply  of  oil  may  be  reduced  by  a 
defective  inlet  or  discharge-check  valve  at  the  mechanical  oiler  or  worn 
pumps.  A  clogged  oil  passage  or  pipe  leading  to  an  important  bear- 
ing point  will  cause  trouble  because  the  oil  cannot  get  between  the 
working  surfaces.  When  simple  compression  pressure  feed  lubricators 
are  employed  the  check  valves  may  be  defective  or  the  container  may 
leak.  Either  of  these  conditions  will  prevent  the  accumulation  of 
pressure  on  the  surface  of  the  oil  and  the  feed  will  not  be  positive.  The 
sight-feed  glasses  may  fill  with  oil  because  the  pipes  leading  from  them 
to  the  engine  are  full,  or  because  the  conductor  is  clogged  with  oil  wax. 
This  gives  sufficient  warning,  however,  and  the  oil  pipe  may  be  easily 
cleared  by  removing  it  and  blowing  it  out  with  air  or  steam  under 
pressure.  It  is  well  to  remember  that  much  of  the  trouble  caused  by 
defective  oiling  may  be  prevented  by  using  only  the  best  grades  of  lu- 
bricant, and  even  if  all  parts  of  the  oil  system  are 'working  properly, 
oils  of  poor  quality  will  cause  friction  and  overheating. 

Defects  in  Cooling  Systems  Outlined. — Cooling  systems  are  very 
simple  and  are  not  liable  to  give  trouble  as  a  rule  if  the  radiator  is 
jkept  full  of  clean  water  and  the  circulation  is  not  impeded.  When 
[overheating  is  due  to  defective  cooling  the  most  common  troubles  are 
'those  that  impede  water  circulation.  If  the  radiator  is  clogged  or  the 
jpiping  or  water  jackets  filled  with  rust  or  sediment  the  speed  of  water 


650  The  Modern  Gasoline  Automobile 

circulation  will  be  slow,  which  will  also  be  the  case  if  the  water  pump 
or  its  driving  means  fail.  Some  cooling  systems  are  so  closely  pro- 
portioned to  the  actual  requirements  that  the  stoppage  of  a  cooling 
fan  will  be  enough  to  cause  the  engine  to  overheat.  Any  scale  or 
sediment  in  the  water  jackets  or  in  the  piping  or  radiator  passages 
will  reduce  the  heat  conductivity  of  the  metal  exposed  to  the  air,  and 
the  water  will  not  be  cooled  as  quickly  as  though  the  scale  was  not 
present. 

The  rubber  hose  often  used  in  making  the  flexible  connections  de- 
manded between  the  radiator  and  water  manifolds  of  the  engine  may 
deteriorate  inside  and  particles  of  rubber  hang  down  that  will  reduce 
the.  area  of  the  passage.  The  grease  from  the  grease  cups  mounted 
on  the  pump-shaft  bearing  to  lubricate  that  member  often  finds  its 
way  into  the  water  system  and  rots  the  inner  walls  of  the  rubber  hose, 
this  resulting  in  strips  of  the  partly  decomposed  rubber  lining  hang- 
ing down  and  restricting  the  passage.  The  cooling  system  is  prone  to 
overheat  after  antifreezing  solutions  of  which  calcium  chloride  forms 
a  part  have  been  used.  This  is  due  to  the  formation  of  crystals  of 
salt  in  the  radiator  passages  or  water  jackets,  and  these  crystals  can 
only  be  dissolved  by  suitable  chemical  means,  or  removed  by  scraping 
when  the  construction  permits. 

Overheating  is  often  caused  by  some  condition  in  the  fuel  system 
that  produces  too  rich  mixture.  Excess  gasoline  may  be  supplied  if 
any  of  the  following  conditions  are  present:  Bore  of  spray  nozzle  or 
standpipe  too  large,  auxiliary  air-valve  spring  too  tight,  gasoline  level 
too  high,  loose  regulating  valve,  fuel-soaked  cork  float,  punctured 
sheet-metal  float,  dirt  under  float  control  shut-off  valve  or  insufficient 
air  supply  because  of  a  clogged  air  screen.  If  pressure  feed  is  utilized 
there  may  be  too  much  gas  pressure  in  the  tank,  or  the  float  controlled 
mechanism  operating  the  shut-off  in  either  the  auxiliary  tank  on  the 
dash  or  the  float  bowl  of  the  carburetor  may  not  act  quickly  enough. 

Some  Causes  of  Noisy  Operation. — There  are  a  number  of  power- 
plant  derangements  which  give  positive  indication  because  of  noisy 
operation.  Any  knocking  or  rattling  sounds  are  usually  produced  by 
wear  in  connecting  rods  or  main  bearings  of  the  engine,  though  some- 
timess  a  sharp  metallic  knock,  which  is  very  much  the  same  as  that 
produced  by  a  loose  bearing,  is  due  to  carbon  deposits  in  the  cylinder 


The  Modern  Gasoline  Automobile  651 

heads,  or  premature  ignition  due  to  advanced  spark-time  lever. 
Squeaking  sounds  invariably  indicate  dry  bearings,  and  whenever  such 
a  sound  is  heard  it  should  be  immediately  located  and  oil  applied  to 
the  parts  thus  denoting  their  dry  condition.  Whistling  or  blowing 
sounds  are  produced  by  leaks,  either  in  the  engine  itself  or  in  the 
gas  manifolds.  A  sharp  whistle  denotes  the  escape  of  gas  under  pres- 
sure and  is  usually  caused  by  a  defective  packing  or  gasket  that  seals 
a  portion  of  the  combustion  chamber  or  that  is  used  for  a  joint  as  the 
exhaust  manifold.  A  blowing  sound  indicates  a  leaky  packing  in 
crank  case.  Grinding  noises  in  the  motor  are  usually  caused  by  the 
timing  gears  and  will  obtain  if  these  gears  are  dry  or  if  they  have 
become  worn.  Whenever  a  loud  knocking  sound  is  heard  careful  in- 
spection should  be  made  to  locate  the  cause  of  the  trouble.  Much 
harm  may  be  done  in  a  few  minutes  if  the  engine  is  run  with  loose 
connecting  rod  or  bearings  that  would  be  prevented  by  taking  up  the 
wear  or  looseness  between  the  parts  by  some  means  of  adjustment. 

As  a  general  rule  the  average  motorist  is  not  sufficiently  informed 
mechanically  to  undertake  repairs  of  worn  motor  parts,  and  whenever 
repairs  of  a  mechanical  nature  are  necessary  it  will  be  much  more  sat- 
isfactory and  cheaper  to  have  them  done  by^  experienced  mechanics  or 
repairmen.  Ordinary  adjustments  may  be  attempted  by  even  the 
inexpert,  but  it  should  be  remembered  that  nothing  may  be  changed 
without  a  good  reason  existing  for  making  the  alteration.  It  is  not 
proposed  to  discuss  the  various  causes  of  noisy  operation  at  length  be- 
cause the  defective  conditions  which  are  evident  by  noisy  action  can 
usually  be  remedied  only  by  skilled  labor.  The  common  defects  of 
the  auxiliary  groups  have  been  mentioned  in  detail,  however,  because 
these  troubles  may  occur  on  the  road  and  it  is  well  for  the  motorist 
to  be  familiar  with  the  common  derangements  that  may  result  in  ir- 
regular engine  operation  or  loss  of  power. 

It  is  not  in  the  scope  of  a  work  of  this  nature  to  analyze  fully  the 
mechanical  derangement  and  methods  of  restoration  because  a  separate 

'  volume  would  be  needed  to  bring  these  points  out  adequately  enough 
to  be  of  value.  If  the  motorist  follows  the  hints  given  in  this  chap- 
ter he  is  not  likely  to  be  stalled  on  the  road  by  simpler  defects  which 
he  can  remedy  as  well  as  the  more  expert.  It  is  well  to  remember 

!  that  common  troubles  can  only  be  located  by  systematic  search  and 


652  The  Modern  Gasoline  Automobile 

that  causes  of  imperfect  engine  action  are  often  located  by  those  who 
do  not  recognize  the  symptoms  because  they  follow  a  logical  process 
of  elimination.  It  must  be  evident  that  all  of  the  defects  outlined 
will  never  happen  within  the  average  experience,  but  the  conditions 
defined  have  been  named  because  they  have  occurred  often  enough  and 
are  sufficiently  common  to  warrant  suspicion  if  trouble  is  experienced. 


CHAPTEE    XIV 

Keeping  Up  the  Motor-Car  Chassis — Common  Defects  of  Clutches  and  Gear- 
sets — Faults  in  Chain-  and  Shaft-Driving  Systems — Troubles  in  Front  and 
Rear  Axles — Adjustment  of  Brakes — Care  of  Miscellaneous  Chassis  Com- 
ponents— Maintenance  of  Body  Finish,  Tops,  and  Upholstery. 

WHEN  any  defects  exist  in  the  power  plant  they  are  immediately 
evidenced  by  lost  power,  misfiring,  overheating,  or  other  positive  indi- 
cations that  cannot  be  neglected.  There  are  many  points  in  the  chas- 
sis that  may  wear  and  be  faulty  in  action  that  will  not  be  immediately 
apparent.  Deterioration  may  exist  in  the  power-transmission  elements 
which  will  mean  a  serious  diminution  in  power,  but  as  the  motor  car 
will  run  more  or  less  capably  the  faults  are  not  generally  known  and 
cannot  be  definitely  located  by  motorists.  There  are  some  points 
where  wear  or  loose  parts  may  directly  concern  the  safety  of  the  oc- 
cupants of  the  car.  For  instance,  any  defect  in  either  the  steering 
gear  or  the  brakes  might  result  disastrously 'in  event  of  failure.  It  is 
not  possible  to  discuss  all  the  points  that  may  need  attention  or  to 
consider  at  length  the  restoration  of  defective  components,  but  it  is 
well  to  consider  some  of  the  common  troubles  which  may  result  in  im- 
perfect operation  and  which  can  be  easily  eliminated. 

Common  Defects  in  Clutches. — Considering  first  the  member  of 
the  transmission  system  that  will  affect  the  efficiency  of  the  entire  as- 
sembly when  deranged,  it  will  be  well  to  discuss  the  troubles  common 
to  the  various  types  of  clutches.  The  defective  conditions  that  most 
often  materialize  are  too  sudden  engagement  which  causes  "  grabbing," 
failure  to  engage  properly,  slipping  under  load,  and  poor  release. 
Clutches  utilizing  a  leather  facing  will  cause  trouble  after  a  time  be- 
cause of  natural  wear  or  some  defect  of  the  friction  facing.  The 
leather  may  be  charred  by  heat  caused  by  slipping,  or  it  may  have 
become  packed  down  hard  and  have  lost  most  of  its  resiliency.  The 
:  clutch  spring  may  be  weakened,  or  broken ;  this  will  cause  the  clutch 
to  slip  even  if  'the  leather  facing  of  the  cone  is  in  good  condition. 

653 


654  The  Modern  Gasoline  Automobile 

The  two  troubles  usually  met  with  by  the  motorist  are  harsh  action, 
as  one  extreme  condition,  and  loss  of  power  through  slippage  as  the 
other. 

When  a  cone  clutch  engages  too  suddenly  it  is  generally  caused 
by  the  surface  of  the  leather  lining  becoming  hard  and  not  having 
sufficient  resiliency  to  yield  to  some  extent  when  first  brought  into 
frictional  contact.  To  insure  gradual  clutch  application  the  facing 
should  be  soft  and  elastic.  If  the  leather  is  not  burned  or  worn  unduly 
it  may  often  be  softened  by  rubbing  it  with  neatsfoot  oil.  Kerosene 
oil  is  often  enough  to  keep  the  clutch  leather  pliable  and  it  possesses 
so  little  lubricating  value  that  the  clutch  members  are  not  liable  to 
slip  because  of  a  reduced  coefficient  of  friction  such  as  often  caused 
by  the  application  of  more  viscous  lubricants.  Kerosene  has  other 
advantages,  among  which  may  be  mentioned  quick  penetration  of  the 
leather  and  not  collecting  grit  or  gumming. 

When  a  cone  clutch  slips  it  is  usually  due  to  a  coating  of  oil  on 
the  frictional  material  that  decreases  the  value  of  the  coefficient  of 
friction  to  such  a  point  that  the  pressure  of  the  clutch  spring  is  not 
enough  to  maintain  sufficient  frictional  contact  between  the  male  and 
female  members  to  insure  driving.  The  remedy  for  this  condition  is 
to  absorb  the  surplus  oil  by  rubbing  a  small  quantity  of  Fuller's  earth 
into  the  leather  surface.  When  the  clutch  cone  is  .in  place  it  is  not 
easy  to  reach  the  surface  of  the  leather,  so  the  first  step  would  be  to 
disengage  or  release  the  clutch  and  to  place  enough  of  the  Fuller's 
earth  on  a  piece  of  paper  or  card  so  it  can  be  sprinkled  into  the  space 
left  between  the  male  and  female  members  when  the  former  is  properly 
released.  Borax  is  sometimes  recommended  for  the  same  purpose  and 
when  the  earth  or  borax  are  not  available  the  carbide  dust  or  lime 
residue  from  the  acetylene-gas  generator  may  be  used  to  advantage. 
If  slipping  is  caused  by  weakening  of  the  clutch  spring  it  may  be 
prevented  by  substituting  springs  of  proper  strength  or  by  increasing 
the  degree  of  compression  of  the  weak  springs  by  some  means  of  ad- 
justment if  provided  for  the  purpose. 

Another  annoying  condition  that  sometimes  obtains  when  a  cone 
clutch  is  used  is  spinning  or  continued  rotation  of  the  male  member 
when  qlutch-spring  pressure  is  released.  This  may  be  the  result  of 
natural  causes  but  it  is  sometimes  caused  by  a  defect  in  the  clutch 


The  Modern  Gasoline  Automobile  655 

mechanism.  If  the  bearing  on  which  the  cone  revolves  when  dis- 
engaged seizes  because  of  lack  of  lubricant  the  male  member  of  the 
clutch  will  continue  to  rotate  even  when  spring  pressure  is  released. 
The  ball-thrust  bearing  employed  to  resist  spring  tension  may  become 
wedged  by  a  broken  ball  and  this  will  cause  the  rotation  of  the  crank 
shaft  to  be  imparted  to  the  cone  member,,  through  the  spring,  which 
must  turn  with  the  crank  shaft  instead  of  remaining  stationary,  as 
would  be  the  case  if  the  ball-thrust  bearing  was  functioning  properly. 

On  those  cars  fitted  with  multiple-disk  clutches  the  same  troubles 
may  be  experienced  as  with  other  types.  If  a  multiple-disk  clutch 
does  not  release  properly  it  is  because  the  surfaces  of  the  plates  have 
become  rough  and  tend  to  drag.  The  plates  of  a  multiple-disk  clutch 
should  be  free  from  roughness  and  the  surfaces  should  always  be 
smooth  and  clean.  Harsh  engagement  also  results  by  the  absence  of 
oil  in  those  types  where  the  disks  are  designed  to  run  into  an  oil  bath. 
Spinning  or  continued  rotation  of  a  multiple-disk  clutch  often  results 
from  seizing  due  to  gummed  oil,  the  presence  of  carbon  or  burned  oil 
between  the  plates  and  sometimes  by  a  lack  of  oil  between  the  mem- 
bers. When  a  multiple-disk  clutch  slips,  it  is  generally  caused  by 
lack  of  strength  of  the  clutch  springs  or  distortion  of  the  plates.  To 
secure  the  best  results  from  a  multiple-disk  clutch  it  is  imperative 
that  only  certain  grades  of  oil  be  used.  If  one  uses  a  cheap  or  in- 
ferior lubricant  it  will  gum  and  carbonize  because  of  the  heat  present 
when  the  plates  slip  or  it  will  have  such  viscosity  that  it  will  gum  up 
between  the  plates.  Most  authorities  recommend  a  good  grade  of 
light  or  medium  cylinder  oil  in  multiple-disk  clutches  where  lubricant 
is  required.  In  some  cases  faulty  multiple-disk  clutch  action  is  due 
to  "  brooming,"  which  is  the  condition  that  exists  when  the  sides  of 
the  keyways  or  the  edges  of  the  disk  become  burred  over  and  prevent 
full  contact  of  the  plates. 

Faulty  clutch  action  has  often  been  traced  to  points  separate  from 
the  clutch  mechanism.  Some  cases  of  failure  of  clutch  to  release  have 
been  found  due  to  imperfect  relation  of  interlocking  levers  and  rods 
3r  wear  in  some  mechanical  parts.  If  a  clutch-shifting  collar  is  worn 
unduly  or  the  small  pins  in  the  rod  connecting  the  clutch  pedal  with 
"he  release  mechanism  have  worn  to  any  extent  the  pedal  may  be  fully 
lepressed  and  yet  the  pressure  of  the  spring  depended  upon  t'o  keep 


656  The  Modern  Gasoline  Automobile 

the  parts  in  contact  will  not  be  reduced  to  any  extent.  Sometimes  the 
emergency-brake  lever  may  have  an  interlocking  leverage  to  release  the 
clutch  when  it  is  applied,  and  when  the  brake  rods  are  shortened  to 
compensate  for  wear  of  the  brakes  the  change  in  length  of  the  operat- 
ing rods  may  throw  out  the  clutch  mechanism  slightly  and  cause  slip- 
ping of  the  clutch  because  the  spring  pressure  may  be  partially  relieved. 

Derangements  in  Change-Speed  Gearing. — As  previously  explained, 
the  simplest  form  of  gearing  to  obtain  various  speed  ratios  is  the 
friction-disk  type.  Failure  to  drive  properly  may  result  from  exces- 
sive oil  on  either  the  face  of  the  driving  disk  or  the  periphery  of  the 
driving  wheel,  lost  motion,  wear  or  spring  at  various  points  in  the 
operating  mechanism,  or  deterioration  of  the  surfaces  of  either  driving 
disks  or  driven  wheel.  If  trouble  is  experienced  in  a  friction  trans- 
mission the  first  point  to  inspect  is  the  condition  of  the  friction  sur- 
faces. If  excessive  deposits  of  oil  have  caused  slipping  it  should  be 
thoroughly  removed  with  gasoline  and  the  surface  of  both  disk  and 
wheel  sprinkled  with  talc  powder.  If  the  face  of  the  aluminum-alloy 
driving  disk  is  grooved  or  roughened,  slipping  is  inevitable  until  the 
disk  is  refaced  absolutely  true.  The  strawboard-fiber  friction  band 
of  the  driven  wheel  may  "  broom  "  out,  and  this  will  cause  slipping 
because  the  surface  is  not  true.  As  a  general  rule,  the  fiber  ring  of 
the  friction  transmission  should  be  renewed  after  it  has  been  used 
from  2,500  to  3,000  miles.  Wear  at  the  countershaft  bearings  will 
produce  a  tendency  for  the  driven  wheel  to  crowd  toward  the  center 
or  edge  of  the  driving  disk,  depending  upon  the  relation  of  the  actual 
line  of  contact  with  the  theoretical  contact  line  drawn  through  the 
disk.  Lost  motion  or  spring  in  the  parts  serving  to  engage  the  fric- 
tion surfaces  will  cause  slipping  because  the  degree  of  pressure  neces- 
sary to  secure  the  frictional  adhesion  required  between  the  members 
to  secure  positive  driving  will  be  reduced. 

The  chief  trouble  with  a  planetary  transmission  is  caused  by  slip- . 
ping  clutcli^ands.  These  are  provided  with  adjustments  that  can  be 
tightened  in  case  of  wear  and  should  grip  positively.  If  either  the 
slow  or  reverse  bands  are  adjusted  too  tight  they  will  bind  on  the 
drums  and  produce  friction,  which  in  turn  will  decrease  the  efficiency 
of  the  drive.  Noisy  action  of  planetary  gearing  is  usually  caused  l>y 
lack  of* lubrication  or  excessive  wear  in  the  gearing.  If  the  oiling  is 


The  Modern  Gasoline  Automobile  657 

properly  taken  care  of  this  condition  will  be  practically  eliminated. 
Sometimes  the  high-speed  clutch  may  slip,  but  most  planetary  gears 
are  provided  with  adjustable  clutches  so  any  wear  may  be  readily 
taken  up. 

When  sliding-gear  transmissions  are  used  the  most  common  defect 
is  difficulty  in  shifting  gears  and  noisy  operation.  The  difficulty  met 
with  in  gear  shifting  is  usually  caused  by  the  edges  of  the  teeth  of 
the  shifting  members  having  burred  over  so  that  they  do  not  pass 
readily  into  the  spaces  between  the  teeth  of  the  gears  they  engage 
with.  Another  cause  of  poor  gear  shifting  is  deterioration  of  the 
bearings  which  may  change  the  center  distances  of  the  shafts  to  a 
certain  degree,  and  the  relation  of  the  gears  may  be  changed  relative 
to  each  other  so  they  will  not  slide  into  mesh  as  freely  as  they  should. 
Noisy  operation  is  usually  due  to  a  defective  condition  of  lubrication, 
and  if  the  gears  are  not  worn  too  much  it  may  be  minimized  to  a  large 
extent  by  filling  the  gear  case  with  oil  of  sufficient  consistency  to 
cushion  the  gear  teeth  and  yet  not  be  so  viscous  that  it  will  not  flow 
readily  to  all  bearing  points.  A  difficulty  in  shifting  is  sometimes  due 
to  binding  in  the  control  levers  or  selective  rods,  and  these  should 
always  work  freely  if  prompt  gear  shifting  is  required.  If  consider- 
able difficulty  is  experienced  in  meshing  the  gears  and  the  trouble  is 
not  found  in  the  gearset,  it  will  be  well  to  examine  the  clutch  to 
make  sure  that  the  driven  member  attached  to  the  gearset  main 
shaft  does  not  "  spin "  or  continue  to  revolve  after  the  foot  pedal 
is  depressed. 

Faults  in  Chain-  and  Shaft-Driving  Systems. — While  power  trans- 
mission by  chains  is  not  as  common  at  the  present  time  in  pleasure- 
car  practice  as  it  has  been  in  the  past,  side-chain  drive  is  used  to 
considerable  advantage  in  motor-truck  work  so  the  following  hints 
on  chain  care  and  adjustment  will  prove  timely.  Much  of  the  trouble 
experienced  when  chain  drive  is  employed  can  be  traced  to  faulty 
design  as  a  basis.  The  teeth  of  the  sprockets  may  ^jt  be  properly 
shaped  and  may  not  be  of  the  form  best  adapted  for  the  chain  designed 
to  run  over  them.  As  most  chains  are  exposed  and  run  without  a 
covering  of  any  kind,  the  action  of  the  road  dust  and  gravel  is  to  com- 
bine with  the  grease  often  rubbed  on  the  outside  on  the  pretext  of 
oiling  the  chain  and  form  an  abrasive  that  will  produce  rapid  wear 


658  The  Modern  Gasoline  Automobile 

between  chain  and  sprocket  and  the  various  links  of  which  the  chain 
is  composed. 

To  obtain  the  best  results  from  chain  drive  the  chains  must  be 
maintained  in  correct  adjustment  by  the  radius  rods  provided  for  the 
purpose.  If  a  chain  is  allowed  to  run  too  loose  it  will  "  whip  "  and  is 
liable  to  climb  the  teeth  of  the  sprocket.  If  the  chain  is  adjusted 
too  tight,  there  will  be  a  strain  on  all  parts  and  it  is  liable  to  "  snap  " 
when  it  leaves  the  sprocket,  especially  if  the  teeth  are  worn  hook  shape. 
A  safe  rule  to  remember  when  adjusting  chains  is  to  have  them  tight 
enough  so  that  it  is  not  possible  to  raise  it  from  the  first  tooth  with 
which  it  meshes  on  either  sprocket,  even  with  the  aid  of  a  lever  such 
as  large  screw  driver  or  tire  iron. 

Chains  must  be  kept  clean  and  properly  oiled.  The  best  method 
of  removing  the  dirt  is  to  take  the  chain  off  the  sprockets  and  let  it 
soak  long  enough  in  a  large  pan  containing  kerosene  so  all  the  dirt 
and  gummed  oil  is  removed  thoroughly  from  all  the  interior  bearing 
surfaces.  It  should  be  gone  over  thoroughly  with  a  stiff  bristle  brush 
until  each  link  works  freely.  The  chain  is  then  immersed  in  a  pan 
of  gasoline  to  remove  any  small  particles  of  grit  that  the  kerosene  may 
have  failed  to  dissolve.  After  the  gasoline  bath  it  is  wiped  with  a 
clean  cloth  until  it  is  dry  and  clean.  The  proper  method  of  chain 
lubrication  is  not  generally  understood  and  in  many  instances  it  is 
accomplished  by  coating  the  outside  of  the  chain  with  a  graphite- 
grease  combination  that  serves  no  useful  purpose,  and  acts  merely 
as  a  collecting  agent  for  dust  and  grit.  The  proper  method  of  chain 
oiling  is  by  immersing  the  cleaned  chain  in  a  molten  mixture  of  tal- 
low or  mineral  grease  and  graphite.  The  entire  chain  is  immersed 
in  this  mixture,  which  is  kept  hot  so  it  will  penetrate  all  the  minute 
interstices  of  the  chain  links  and  produce  a  thin  coating  of  lubricant 
at  all  the  working  surfaces.  The  chain  is  removed  from  the  bath 
of  lubricant  and  while  still  hot  all  surplus  oil  is  wiped  off  until  the 
outside  of  the  chain  is  dry  and  clean.  This  method  insures  pro  pet- 
lubrication  of  the  many  small  joints  usually  neglected  and  should  be 
done  every  thousand  miles. 

But  little  trouble  is  experienced  with  shaft-driving  systems  bo- 
.  cause  the  driving  gearing  and  universal  joints  are  so  well  enclosed  on 
modern  axles.  The  bevel-driving  gears  are  packed  in  lubricant 


The  Modern  Gasoline  Automobile  659 

as  a  rule,  and  but  little  wear  is  noted,  even  after  several  seasons  of  use. 
An  important  point  to  observe  with  all  forms  of  axles  is  to  make 
sure  that  the  antifriction  bearings  are  kept  properly  cleaned  and 
oiled.  The  oil  used  should  contain  no  acid  and  should  be  of  the 
best  quality.  Care  should  be  taken  in  washing  the  car  so  that  water 
will  be  prevented  from  entering  the  bearing  points.  If  the  bevel 
gears  of  the  rear  axle  grind  it  is  due  to  improper  adjustment  or  ex- 
cessive wear  between  the  teeth.  Grinding  sounds  usually  result  from 
meshing  the  gears  too  deeply,  while  loose  adjustment  is  manifested  by 
rattling. 

Care  of  Front  Axles  and  Steering  Connections. — The  wheels  of 
front  axles,  especially  on  the  lighter  .runabouts  fitted  with  ball  bearings 
of  the  pressed  steel  cup  and  adjustable  cone  type,  should  be  carefully 
examined  from  time  to  time.  As  a  general  rule,  the  wear  upon  the 
cones  of  such  bearings  is  rapid  because  of  the  stresses  obtaining  at 
this  point.  It  is  well  to  jack  up  the  axle  from  time  to  time  and  turn 
the  wheels  by  hand  to  insure  that  they  turn  freely,  and  to  move  them 
to  see  if  there  is  any  play  or  loss  motion  that  would  indicate  either 
wear  or  poor  adjustment  of  the  bearings.  When  examined  the  balls 
should  be  perfectly  round  and  smooth  and  the  cones  and  races  should 
have  unbroken  surfaces.  Care  should  be'*taken  in  adjusting  the  cone 
so  the  wheels  turn  freely  and  yet  they  should  be  tight  enough  so  no 
play  will  exist  between  the  front  wheel  and  the  bearings.  If  the 
cones  are  adjusted  up  too  tight  the  balls  will  be  wedged  in  such  a 
way  that  they  will  soon  cut  into  the  race  ways.  As  a  general  rule, 
annular  ball  bearings  will  need  but  little  attention.  The  steering 
knuckles  should  be  looked  over  to  see  that  the  spindle  bolts  are  right, 
and  the  various  joints  of  the  drag  link  and  tiebar  should  be  carefully 
examined  for  any  lost  motion.  It  is  desirable  to  encase  all  the  small 
joints  forming  part  of  the  steering  system  in  small  leather  bags  packed 
with  lubricant,  because  if  these  joints  are  kept  well  oiled  and  protected 
from  grit  there  will  be  but  little  wear  at  those  points. 

Adjustment  of  Brakes. — The  means  of  adjusting  brakes  may  be 
easily  ascertained  by  inspection.  If  brakes  do  not  hold  properly  and 
the  friction  facing  is  in  good  condition  and  free  from  oil,  the  failure 
to  grip  the  drum  is  probably  due  to  wear  in  the  operating  leverage. 
On  some  form  of  brakes,  notably  those  which  are  expanded  by  a  toggle 


660  The  Modern  Gasoline  Automobile 

joint  or  cam  motion,  compensation  for  wear  of  the  brake  shoes  is 
often  made  by  shortening  the  rods  running  from  the  brake  to  the 
operating  lever.  External  brakes  are  usually  provided  with  an  adjust- 
ment on  the  brake  band,  which  permits  one  to  draw  the  ends  of  the 
band  closer  together  and  take  up  much  of  the  lost  motion  between 
the  band  and  the  brake  drum.  When  adjusting  brakes  it  is  necessary 
to  make  the  adjustment  so  the  brakes  will  take  hold  together.  If 
one  member  is  adjusted  so  that  it  will  grip  its  drum  before  the  other 
does,  there  will  be  considerable  strain  on  the  tires  and  a  tendency  to 
side  slipping  every  time  the  brakes  are  applied.  After  the  brakes  are 
adjusted  it  is  well  to  jack  up  the  axle  to  make  sure  that  the  wheels 
turn  freely  and  that  there  is  no  binding  between  the  brake  members 
and  the  drums  on  the  hubs.  If  the  brakes  are  adjusted  too  tightly 
the  friction  will  cause  heat  after  the  car  has  been  run  a  short  distance, 
and  this  increase  in  temperature  is  a  very  good  indication  of  power 
loss  by  friction  between  the  brake  and  the  drum.  If  the  brakes  are 
not  adjusted  sufficiently  tight  a  full  movement  of  the  pedal  or  hand 
lever  will  prove  inadequate  to  apply  the  brakes  tight  enough  to  stop 
rotation  of  the  wheels.  The  bearings  used  in  rear  wheels  are  usually 
of  the  nonadjustable  antifriction  types  and  require  practically  no  at- 
tention except  to  keep  them  properly  oiled  and  cleaned. 

Care  of  Miscellaneous  Chassis  Components. — A  common  trouble 
with  all  types  of  motor-car  frames  is  that  after  a  period  of  use  they 
may  sag  down  at  the  center.  This  condition  may  produce  difficulty  in 
clutch  shifting  or  gear  actuation  because  it  may  cause  cramping 
or  binding  of  the  operating  mechanism.  A  sagging  frame  is  usually 
strengthened  and  brought  back  into  place  by  a  strut  rod  and  turn 
buckle  arrangement  which  may  be  installed  under  the  defective  mem- 
ber by  any  competent  mechanic.  The  various  frame  members  some- 
times become  loose  owing  to  the  play  in  the  rivets  caused  by  the  frame 
distortions.  Another  point  of  importance  is  lost  motion  in  spring 
hangers  and  shackles  and  often  the  bolts  passing  through  the  spring 
eye  and  the  shackle  links  may  be  found  worn  half  through  if  in- 
spected after  a  season's  use.  On  many  cars  no  provision  has  been 
made  for  lubricating  these  points  and  the  deterioration  produces 
squeaking  and  rattles  when  the  car  is  operated  over  rough  roads.  If 
the  spring  action  is  harsh  and  if  these  members  squeak  the  spring 


The  Modern  Gasoline  Automobile  661 

leaves  should  be  pried  apart  after  the  spring  clips  have  been  loosened 
a  trifle  and  oil  introduced  between  the  leaves. 

Back  lash  in  the  steering  mechanism  is  often  a  source  of  annoyance 
to  motorists,  but  if  it  is  present  only  in  the  reduction  gears  at  the 
bottom  of  the  steering  posts  it  is  not  a  serious  defect.  On  some  types 
of  worm  and  worm-wheel  gears  the  worm-wheel  shaft  is  provided  with 
eccentric  bushings  and  a  certain  amount  of  wear  may  be  taken  up  by 
turning  these  so  that  the  gear  teeth  are  brought  into  closer  relation. 
In  cases  where  the  control-lever  rods  go  down  through  the  center  of  the 
steering  column  accumulations  of  rust  will  sometimes  cause  stiff  action. 
This  condition  is  easily  remedied  by  removing  the  rod  and  surround- 
ing tube  member,  cleaning  out  the  rust,  and  putting  the  parts  back 
after  they  have  been  thoroughly  oiled. 

The  suggestions  given  in  this  chapter  and  the  preceding  one  should 
prove  of  value  to  all  motorists  by  assisting  them  in  securing  a  knowl- 
edge of  the  more  common  troubles  incidental  to  motor-car  operation. 
The  general  suggestions  given  cannot  be  considered  applying  to  any 
specific  case  because  they  are  so  general  in  character,  and  obviously  the 
differences  in  construction  of  the  various  cars  will  have  to  be  taken 
into  consideration  in  attempting  to  apply  the  suggestions  given 
advantageously.  Enough  of  the  ordinary  defects  have  been  men- 
tioned so  that  almost  any  ordinary  derangement  can  be  located  and 
remedied. 

Maintenance  of  Body  and  Upholstery. — Many  motorists  are  at  loss 
to  understand  the  reason  for  quick  deterioration  of  the  brightly  var- 
nished surfaces  of  a  motor-car  body  that  has  been  in  use  for  some  time. 
The  paint  may  be  blistered  or  cracked  or  the  finish  may  be  spotted 
at  various  points.  Bodies  that  were  formerly  black  will  assume  a  blu- 
ish tinge  and  bright  varnish  will  soon  become  dull.  If  the  car  is  an 
expensive  one,  the  motorist  is  justified  in  expecting  a  degree  of  finish 
that  will  endure,  but  those  who  purchase  cheaper  cars  must  expect 
to  lose  the  bright  finish  after  the  car  has  been  used  for  a  time.  Where 
cars  are  manufactured  in  large  quantities,  the  varnish  is  often  applied 
before  some  of  the  under  coats  are  thoroughly  dried,  and  the  result 
will  be  a  series  of  blisters.  Another  result  of  hasty  manufacture  and 
of  putting  the  car  in  service  soon  after  painting  is  spotting.  This  is 
produced  by  dry  mud  which  extracts  some  of  the  oil  or  gum  from 


662  The  Modern  Gasoline  Automobile 

the  varnish  and  may  often  be  caused  by  actual  chemical  action  of 
alkaline  mud.  The  mud  of  city  streets,  especially  at  points  where 
there  is  a  great  deal  of  animal  traffic,  is  highly  charged  with  ammonia,, 
and  in  certain  clay  or  lime  districts  the  mud  is  very  destructive  to  the 
varnish  luster. 

Even  when  a  car  has  been  properly  varnished  and  finished  there 
are  many  conditions  for  which  the  motorist  is  directly  or  indirectly 
to  blame  which  will  ruin  even  the  highest  grade  of  paint  and  varnish. 
For  instance,  when  cars  are  cleaned  at  garages  various  soaps  and  wash- 
ing compounds  are  used  which  contain  alkaline  materials  to  assist 
in  removing  dirt  and  oil  but  which  are  very  destructive  to  the  highly 
finished,  varnished  surfaces.  Most  of  the  soaps  upon  the  market  con- 
tain ingredients  which  have  a  chemical  action  on  the  oils  of  paint  and 
causes  it  to  deteriorate.  There  are  soaps  which  do  not  damage  painted 
surfaces,  but  these  are  usually  more  costly  and  require  more  care  and 
labor  to  remove  the  dirt  accumulation  so  they  are  not  apt  .to  be  gen- 
erally used.  The  grades  of  soap  that  act  the  quickest  in  cutting  grease 
are  those  that  will  more  quickly  dull  the  surfaces  of  the  body. 

Some  very  good  carriage  painters  go  so  far  as  advising  that  no 
soap  be  used  on  finely  varnished  surfaces.  Some  painters  advise 
against  dusting  off  a  car  and  claim  that  accumulations  of  this  sub- 
stance should  be  removed  from  the  surface  by  washing.  It  is  con- 
tended that  wiping  off  the  dust  will  have  the  effect  of  scratching  the 
varnished  surfaces  and  that  the  best  method  of  removing  either  dust, 
mud,  or  dirt,  is  to  flush  the  surfaces  with  water  from  a  hose.  After 
as  much  of  the  dirt  has  been  removed  by  this  method  as  possible  a 
sponge  may  be  used,  but  care  must  be  taken  that  no  grit  is  permitted 
to  collect  beneath  the  sponge  and  that  the  stream  of  water  from  the 
hose  be  always  kept  at  work  ahead  of  the  sponge. 

If  any  grease  is  present  on  the  running  gear  it  should  be  removed 
with  gasoline  or  benzene,  and  while  these  substances  may  deaden  the 
varnished  surfaces  temporarily  the  blemish  will  not  remain  if  the  dull 
varnish  is  polished  with  a  clean  soft  cloth  wet  with  linseed  oil.  The 
finish  of  many  automobiles  is  ruined  by  allowing  accumulations  of  oil 
or  asphalt  from  freshly  tarred  or  oiled  roads  to  remain  on  the  body 
work.  These  substances  should  not  be  allowed  to  remain  any  longer 
than  possible,  and  if  the  oil  or  asphalt  has  become  hardened,  it  may 


The  Modern  Gasoline  Automobile  663 

be  dissolved  by  using  naphtha,  vaseline,  or  even  butter.  After  the  oily 
accumulations  have  been  dissolved  the  car  should  be  very  carefully 
washed  to  remove  all  traces  of  the  oily  mud  or  the  solvents. 

Of  course  there  are  portions  of  the  car  where  it  is  difficult  to  have 
the  paint  stay  in  good  condition.  The  paint  is  often  burned  off  that 
part  of  the  hood  on  a  gasoline  machine  adjacent  the  exhaust  pipe  or 
on  those  portions  of  the  hood  of  a  steam  car  which  cover  the  boiler 
or  burner.  Any  part  of  the  hood  subjected  to  considerable  heat  will 
become  discolored  after  a  time  and  if  the  heat  is  intense  the  paint  will 
burn  and  blister.  If  care  is  taken  to  keep  the  body  properly  washed 
by  using  only  the  best  grade  of  carriage  soap  obtainable  and  only 
clean  water,  sponges,  and  chamois  cloths,  the  body  finish  will  be  pre- 
served for  a  much  longer  time  than  if  washing  is  neglected  and  the 
mud  or  dirt  allowed  to  dry  on  the  varnished  surfaces.  The  use  of 
quick-acting  soaps  should  be  avoided  as  much  as  possible  and  tar  or 
oil  accumulations  should  be  removed  as  soon  as  conditions  will  permit. 
If  a  car  is  kept  in  a  barn  or  shed  housing  horses  or  cattle,  or  adjacent 
to  a  stable  the  fumes  of  ammonia  will  soon  cause  deterioration  of  the 
paint  and  varnish.  One  should  never  touch  dusty  surfaces  with  the 
hands  or  attempt  to  remove  the  dust  by  brushing  off  with  a  cloth. 
As  a  general  rule,  an  automobile  body  will  need  to  be  gone  over  every 
season.  The  first  year  that  the  car  is  in  use  the  paint  should  be  in 
good  enough  condition,  if  proper  attention  has  been  paid  to  washing, 
so  that  a  coat  of  varnish  will  suffice  to  restore  the  body  to  its  pristine 
brilliancy.  A  car  that  has  been  used  more  than  one  season  will  need 
both  painting  and  varnishing  to  make  a  good  job. 

The  matter  of  cleaning  and  caring  for  tops  and  upholstery  is  also 
one  that  should  be  considered  to  some  extent.  Mohair  tops  are  usu- 
ally fitted  to  high-grade  cars,  leather  to  medium-priced  cars,  and  imi- 
tation leather  or  pantosote  on  the  cheaper  cars.  In  cleaning  mohair 
tops,  it  is  necessary  to  remove  not  only  dust  and  dirt  but  particles  of 
grease  or  oily  matter  thrown  up  against  it  by  the  wheels  from  erther 
the  road  surface  or  portions  of  the  mechanism.  Dust  should  be  re- 
moved with  a  moist  sponge,  while  grease  or  oil  stains  can  be  taken 
off  by  a  sponge  and  good  soapsuds.  Leather  and  imitation-leather 
tops  should  be  treated  with  some  form  of  preservative.  Some  dress- 
ings may  be  purchased  all  ready  mixed  and  may  be  applied  by  the 


664  The  Modern  Gasoline  Automobile 

motorist  himself.  Others  may  be  prepared  at  very  little  expense. 
Shabby  leather  may  be  made  to  look  brighter  by  rubbing  over  the 
surface  with  either  linseed  oil  or  the  well-beaten  white  of  an  egg 
mixed  with  a  little  black  ink.  Before  applying  any  type  of  dressing, 
it  is  advised  to  go  over  the  surface  with  neatsfoot  oil  until  it  has 
been  properly  softened,  and  often  the  oil  treatment  will  be  sufficient  for 
all  practical  purposes. 

The  following  recipe  is  given  as  a  good  preservative  for  leather. 
It  is  composed  of  six  parts  of  spermaceti,  eighteen  parts  of  beeswax, 
five  parts  of  asphalt  varnish,  five  parts  black  vine  twig,  two  parts 
Prussian  blue,  one  part  nitrobenzol,  one  part  powdered  borax,  and 
sixty-six  parts  oil  of  turpentine.  The  wax  is  melted  and  the  borax 
is  added,  after  which  the  mixture  is  stirred  until  a  jellylike  mass  is 
formed.  In  another  pan  the  spermaceti  is  melted,  the  varnish  which 
has  been  previously  mixed  with  turpentine  is  added,  and  the  mass 
stirred  well  and  added  to  wax  mixture  in  the  other  vessel.  The  color 
is  the  last  ingredient  added,  this  having  been  previously  rubbed  smooth 
with  a  little  of  the  mixture.  The  material  is  applied  with  a  brush 
about  once  a  week  in  small  quantities  and  is  wiped  well  with  a  soft 
cloth  to  polish  after  application. 

Another  formula  for  giving  new  life  to  leather  tops  or  upholstery 
is  given  as  follows : 

Ground  Ruby  Shellac 2 . 25    parts 

Dark  Resin 91    parts 

Sandaric 115  parts 

Gum  Resin 115  parts 

Aniline  Black  (Spirit  Soluble) 115  parts 

Lamp  Black 115  parts 

Wood  Alcohol 22 . 50    parts 

The  first  step  in  preparing  this  mixture  is  to  dissolve  the  sandaric, 
dark  resin,  gurri  resin,  and  shellac  in  the  alcohol;  next  the 
aniline  black  is  added  and  finally  the  lamp  black,  which  has  been 
ground  to  a  paste  with  a  little  of  the  liquid,  is  mixed  in.  After  the 
whole  has  been  thoroughly  mixed  it  is  filtered.  This  is  applied  to 
the  top  or  upholstery  with  a  brush  and  is  polished  with  a  soft  cloth 
or  brush. 


The  Modern  Gasoline  Automobile  665 

On  genuine  leather  tops,  upholstery,  and  for  the  leather  straps 
holding  the  top  a  good  grade  of  harness  oil  is  often  sufficient.  The 
following  will  be  found  an  effective  mixture : 

Oil  of  Turpentine 2      ozs. 

Lamp  Black y%  oz. 

Neatsfoot  oil 10      ozs. 

Vaseline 4      ozs. 

The  lamp  black  is  mixed  with  the  turpentine  and  the  neatsf oot  oil, 
and  the  vaseline  is  thinned  by  heating  it,  and  the  ingredients  are 
mixed  by  shaking  together.  When  the  mixture  cools  it  will  be  in 
the  form  of  a  grease  or  paste  which  is  rubbed  well  into  the  leather  to 
be  preserved  or  softened. 

If  a  car  has  been  used  on  a  wet  or  stormy  day  the  top  should  be 
kept  up  until  it  is  thoroughly  dry,  as  if  it  is  inserted  in  the  top  case 
or  folded  while  wet  the  lining  might  mildew  or  rot.  In  folding  tops 
care  should  be  taken  to  have  the  folds  even  and  to  have  as  few 
wrinkles  as  possible.  The  various  bows  comprising  the  framework  of 
the  top  should  be  separated  by  small  rubber  pads  and  the  whole  firmly 
strapped  together  by  leather  bands  applied  at  each  side  of  the  folded 
top  frame  to  prevent  rattle. 

Upholstery  is  usually  preserved  by  slip  covers  of  various  grades  of 
cloth  applied  to  the  cushions  and  to  the  backs  of  the  seats.  As 
most  cushions  and  seat  backs  are  upholstered  with  leather  or  the 
various  fabrics  imitating  it,  the  same  dressings  that  have  been  recom- 
mended for  tops  may  be  used  to  advantage  in  treating  the  cushions 
and  seat  backs.  In  some  of  the  higher-priced  cars,  especially  of  the 
closed-body  form,  various  grades  of  broadcloth,  Bedford  cord,  or  other 
textile  fabrics  are  used.  When  these  become  dirty  they  must  be 
treated  very  carefully  and  by  an  experienced  cleaner  because  ordinary 
methods  of  removing  grease  spots  will  cause  unsightly  discolorations 
of  the  fine  fabrics.  Where  high-grade  upholstering  materials  are  used 
slip  covers  are  really  necessary.  These  should  be  kept  in  place  at  all 
times  that  the  passengers  are  in  ordinary  street  or  business  dress,  but 
may  be  removed  and  the  clean  upholstering  used  at  such  times  that 
it  is  desirable  not  to  dirty  the  clothing  as  when  evening  clothes 
are  worn.  If  the  cushions  or  seat  backs  are  torn,  or  otherwise  dam- 


666  The  Modern  Gasoline  Automobile 

aged,  restoration  can  only  be  made  by  an  upholsterer  or  carriage 
trimmer.  Whenever  any  of  the  preservative  dressings  are  applied 
to  the  upholstery,  it  is  well  to  wipe  off  all  traces  of  the  dressing  very 
carefully  in  order  that  it  will  not  soil  the  clothing. 

How  to  Keep  the  Hands  Soft. — The  mechanism  of  an  automobile 
is  very  dirty  and  the  fact  that  this  grime  is  very  hard  to  remove  from 
the  hands  often  deters  motorists  from  making  necessary  adjustments. 
It  is  not  difficult  to  keep  the  hands  soft  and  to  remove  dirt  or  grease 
accumulations  if  proper  precautions  are  taken  before  the  work  is 
started.  The  first  operation  is  to  coat  the  hands  thoroughly  with  a 
fine  soft-soap  paste  and  rub  it  thoroughly  into  the  pores  of  the  skin 
and  under  the  finger  nails  before  starting  in  to  work.  After  a  little 
rubbing  the  soap  is  absorbed  by  the  pores  and  apparently  disappears. 
When  the  repairs  are  completed  the  hands  are  dipped  in  water  and  a 
little  powdered  pumice  stone  or  sawdust  soaked  in  kerosene  oil  is 
rubbed  in  thoroughly  until  the  soap  is  brought  to  a  lather.  The  hands 
are  then  washed  in  the  ordinary  manner  and  the  dirty  soap  removed 
from  under  the  finger  nails.  As  the  pores  are  filled  with  soap  they 
cannot  fill  with  dirt  and  the  protecting  influence  of  the  soap  under 
the  nails  keeps  out  the  dirt,  which  cannot  collect  at  points  where  it  is 
not  readily  accessible.  Bran  or  sawdust  moistened  in  kerosene  and 
used  in  connection  with  ordinary  soap  is  very  good  to  remove  the  dirt 
without  injuring  the  hands.  Various  grades  of  prepared  hand  soap 
may  be  obtained  on  the  market  but  most  of  these  contain  ingredients 
which  injure  the  skin.  Strong  alkalies  are  used  in  many  cases  to 
remove  the  dirt  and  such  compounds  should  not  be  used  if  they  dis- 
color the  can  in  which  they  are  sold.  Any  substance  that  will  have  a 
strong  enough  chemical  action  on  metal  to  corrode  it  is  not  fit  to  be 
used  on  the  skin. 

A  Few  Words  of  Caution  in  Conclusion. — In  order  to  obtain  the 
best  results  from  an  automobile  it  is  imperative  that  the  owner  famil- 
iarize himself  with  all  the  details  of  its  operation  unless  he  is  sufficient- 
ly wealthy  to  hire  help  to  drive  and  look  after  the  car.  All  car 
owners  who  expect  to  look  after  their  own  machines  must  first  acquire 
a  knowledge  of  all  details  of  the  oiling  system  and  the  various  points 
of  the  chassis  that  require  oiling.  More  machines  wear  out  because 
of  lack  of  proper  attention  to  lubrication  than  because  of  the  amount  of 


The  Modern  Gasoline  Automobile  667 

work  done,  as  present  designs  of  modern  automobile  parts  are  thor- 
oughly reliable  and  can  be  depended  on  to  give  satisfactory  service 
for  many  thousand  miles  without  mechanical  deterioration.  These 
results  can  only  be  obtained  if  care  is  taken  to  keep  every  moving 
part  clean  and  properly  lubricated. 

The  rules  given  for  the  proper  care  of  tires  should  be  followed 
to  the  letter  because  the  item  of  tire  maintenance  is  one  of  the  most 
costly  of  all  the  expenses  incidental  to  motor-car  operation.  Careful 
driving  and  the  judicious  control  of  the  car  will  do  much  toward 
maintaining  efficiency  of  the  mechanism  and  it  is  well  to  remember 
that  more  harm  can  be  done  to  the  various  chassis  parts  by  a  fast 
run  of  a  few  hundred  miles  than  will  result  from  thousands  of  miles  of 
slower  driving.  It  is  well  to  drive  cautiously  at  all  times  and  to 
remember  that  other  users  of  the  highways  have  rights  that  must  be 
respected.  When  operating  a  car  on  rough  roads  the  speed  should 
always  be  reduced  to  a  low  point.,  and  usually  the  comfort  of  the  pas- 
sengers will  provide  the  best  indication  of  whether  the  car  is  being 
operated  at  the  proper  speed  or  not. 

As  soon  as  any  parts  are  defective  and  repairs  are  necessary  that 
cannot  be  made  by  the  motorist  himself  the  work  of  restoration  should 
be  given  to  a  competent  mechanic  even  if'his  charges  are  higher. than 
those  having  less  experience.  At  the  end  of  every  active  riding  season 
and  before  the  inception  of  the  new  period  of  service  the  car  should  be 
thoroughly  overhauled,  and  one  who  is  able  to  appreciate  the  value  of 
this  work  of  restoration  and  who  takes  care  of  the  mechanism  always 
has  a  machine  that  is  in  good  running  order  and  that  will  give  satis- 
factory service.  Many  motorists  are  short-sighted  because  they  neg- 
lect the  mechanism  and  run  the  machine  as  long  as  it  will  hold  to- 
gether. As  a  rule,  these  are  the  pessimists  who  hold  that  automobiles 
are  an  unreliable  and  costly  possession. 


INDEX 


Accessibility  of  Crankcase  Parts,  216. 
Acetylene    Gas,    Compressed,    572. 
Acetylene   Gas   Generator,   570. 
Acetylene    Gas,    Lamps    for,    572. 
Acetylene  Gas  Lighting  System,  570. 
Acetylene  Gas  Production,  570. 
Acid  Cure  Vulcanizer,  545. 
Acid  Test  in  Cooling  Mixtures,  635. 
Ackerman  Pivoted   Axles,  474. 
Action  of  Acetylene  Generator,  570. 
Action  of  Automatic  Governor,  263. 
Action  of  Bubbling  Carburetor,  248. 
Action    of   Compensating    Carburetor, 

255. 

Action  of  Differential  Gearing,  491. 
Action  of  Dynamo,  Principles  of,  317. 
Action    of   Dynamo    Speed    Governor, 

319. 

Action  of  Float  Feed  Carburetor,  254. 
Action    of    Simple    Ignition    System, 

328. 

Action  of  Solid  and  Air  Tires  Com- 
*  pared,  518. 

Action    of    Steering    Gear,   475. 
Action   of   Storage    Battery,   313. 
Action    of   Venturi    Tube,    257. 
Action  of  Wick  Carburetor,  247. 
Actual  Duration  of  Strokes,  91. 
Adjustable     Springs,     Use     on     Cone 

Clutch,   418. 
Adjusting    Carburetors,    Methods    of, 

648. 
Adjustment     for    Wear    of    Steering 

Gears,  478. 


Adjustment   of   Brakes,    660. 
Adjustment   of  Carburetors,   256. 
Adjustment  of  Driving  Chains,  658. 
Adjustment  of  Front  Wheel  Bearings, 

659. 

Advantages  of   Concentric   Float    De- 
sign, 256. 

Advantages   of   Dynamo,  317. 
Advantages  of  En-Bloc  Construction, 

124. 

Advantages  of   Engine    Starters,   561. 
Advantages  of  Gasoline  Car,  37. 
Advantages     of     Left-Hand     Control, 

627. 

Advantages  of  Long  Stroke,  126. 
Advantages  of  Off-set  Cylinders,  130. 
Advantages  of  Planetary  Gearing,  439. 
Advantages  of  Selective  Sliding  Gear 

System,  447. 

Advantages  of  Steam  Car,  37. 
Advantages    of    Three-Point    Support, 

114. 
Advantages     of     Underslung     Frame, 

461. 

Advantages  of  Worm  Gearing,  495. 
Air  and  Gasoline  Proportions,  240. 
Air  Blower  for  Cooling  Cylinders,  400. 
Air   Bottle   for   Tire  Inflation,   552. 
Air  Circulating  Fan,  396. 
Air  Cooled  Engine  Design,  398. 
Air  Cooling,  by "  Convection,   397. 
Air  Cooling,   by  Radiation,  397. 
Air  Cooling,  Franklin  Method,  403. 
Air    Cooling,    Frayer-Miller    Method, 

403. 
Air  Cooling  Methods,  390. 


669 


670 


Index 


Air  Cooling  Two-Cycle  Motor,  402. 

Air  Cooling,  Use  of  Auxiliary  Exhaust 
Valve,  399. 

Air  Currents,  Direction  of,  65. 

Air  Pressure,  Correct  for  Tires,  551. 

Air  Pressures,  Increase  by  Heat,  551. 

Air  Resistance  and  Body  Design, 
62. 

Air  Resistance,  Power  to  Overcome, 
64. 

Air  Starters,  564. 

Air  Valve  for  Pneumatic  Tires,  522. 

Air  Valve  Troubles,  554. 

Alarms  for  Motor  Cars,  588. 

Alcohol  and  Acetylene  Combination, 
236. 

Alcohol,  Denatured,  236. 

Alcohol,  Glycerine,  and  Water  Solu- 
tions, 636. 

Alloy  Steels  for  Springs,  471. 

Ampere,  Definition  of,  312. 

Amplex  Two-Cycle  Motor,  218. 

Analysis  of  Typical  Engine  Stoppage, 
642. 

Animal  Drawn  Conveyance,  Steering, 
473. 

Anti-Freezing  Compounds,  634. 

Anti-Freezing  Compounds,  Glycerine, 
635. 

Anti-Freezing  Solutions,  Denatured  Al- 
cohol, 636. 

Anti-Skid  Treads  for  Tires,  525. 

Application   of  Liquid  Fuels,  237. 

Applying  Non-Skid  Chains,  530. 

Arrangement  of  Contacts  in  Timers, 
326. 

Artillery  Wheel,  Construction  of,  511. 

Assembly,  Hupp  Cam  Case,  154. 

Assembly  of  Typical  Chassis,  51. 

Automatic  Governor  Action,  263. 

Automatic  Governor  for  Dynamo 
Speed,  319. 

Automatic  Governor  for  Gas  Supply, 
263. 


Automobile  and  Locomotive,  Compari- 
son of,  47. 

Automobile    Design,    Progress    of,   39. 
Automobile,    Necessary    Elements    of, 

44. 
Automobile   Power  Plant  Control  by 

Governor,  610. 
Automobile   Power  Plant  Control  by 

Spark  Lever,  610. 
Automobile   Power   Plant  Control   by 

Throttle,  610. 
Automobile  Power  Plants,  Flexibility 

of,  609. 
Automobile  Power  Plant,   Method   of 

Starting,  607. 

Automobile,  Power  Transmission  Sys- 
tem of,  408. 

Automobile  Steering  Gears,  475. 
Automobile  Tires,  Cushion  Types,  534. 
Automobile  Tires,  Forms  of,  517. 
Automobile  Tires,  Pneumatic,  519. 
Automobile  Tires,   Solid   Rubber,  537. 
Automobile  Wheels,  Cast  Metal,  512. 
Automobile  Wheels,  Forms  of,  509. 
Automobile  Wheels,  Resilient,  515. 
Automobile    Wheels,    Stamped   Metal, 

512. 
Automobile  Wheels,  Suspension  Type, 

513. 

Automobile  Wheels,  Wire,  509. 
Automobile  Wheels,  Wood,  509. 
Automobiles,  How  Steered,  473. 
Automobiles,  Winter  Care  of,  634. 
Automobiles,  Yearly  Output,  35. 
Auxiliary  Air  Valve  Forms,  261. 
Auxiliary  Exhaust  Valves,  Utility  of, 

399. 
Auxiliary    Friction    Pads    in    Clutch, 

418. 

Axle   Loads,  Influence   on   Tires,  550. 
Axles,  Ackerman  Pivoted,  474. 
Axles,  Methods  of  Spring  Attachment, 

471. 
Axles,  Rear,  487. 


Index 


671 


B 

Back  Lash  in  Steering  Mechanism, 
661. 

Ball  Bearing  Connecting  Rod,  194. 

Ball  Bearing  Crankshafts,  205. 

Ball  Thrust  Bearings  in  Steering 
Gears,  481. 

Barrel   Type   Crankcase,  215. 

Battery  Capacity,  Tests  for,  645. 

Battery  for  Electric  Lighting,  5-73. 

Battery  Ignition  Systems,  341. 

Battery  Ignition  Systems,  Four-Cylin- 
der, 341. 

Bearings,  Ball  Thrust,  in  Steering 
Gears,  481. 

Bearings  for  Connecting  Rods,  193, 

Bearings  for  Front  Hubs,  483. 

Benzol  and  Its  Properties,  233. 

Bevel  Gear  Driving,  493. 

Bevel  Seat  Valve,  146. 

Blower  Type   Air  Fan,   400. 

Blowing  and  Whistling  in  Power 
Plant,  Causes  of,  651. 

Blowing  Back,   Cause   of,   177. 

Blow   Out,   Cause  of,  552. 

Blow  Out,  Repair  of,  555. 

Body  Design  and  Air  Resistance,  62. 

Body  Design  and  Dust  Disturbance, 
62. 

Body  Design,  Stream  Line,  67. 

Body  Finish  and  Upholstery,  Mainte- 
nance of,  661. 

Bore  and  Stroke  Ratio,  126. 

Brakes,  Combination,  502. 

Brakes,  Effect  on  Side  Slip,  505. 

Brakes,  External  Contracting,  501. 

Brakes,  Form  Used  on  Wagons,  499. 

Brakes,  Front  Wheel,  505. 

Brakes,  Internal  Expanding,  501. 

Brakes,  Method  of  Mounting,  503. 

Brakes,  Methods  of  Adjusting,  660. 

Brakes,  Multiple-Disk  Type,  504. 

Brakes,  Operation  of  Front  Wheel,  507. 


Brakes,  to  Stop  Cone  Clutch  Rota- 
tion, 420. 

Brakes,  to  Stop  Three  Plate  Clutch 
Rotation,  424. 

Brakes,  Utility  of,  499. 

Breeze  Carburetor  Construction,  278. 

Brightly  Finished  Parts,  Care  of,  601. 

"  Brooming  Out "  of  Friction  Ring, 
656. 

Bubbling  Carburetor  Action,  248. 

Buick  Control  System,  624. 

Bulb  Retention,  Edison  Screw  Base, 
577. 

Bulb  Retention,  Edi-Swan  Base,  577, 

Built  Up  Camshafts,  198. 

Built  Up  Crankshaft,  200. 

Built  Up  Induction  Pipe,  294. 


Cadillac  Starting  System,  568. 

Calcium  Chloride  Solutions,  634. 

Calcium  Chloride  Solutions,  Freezing 
Points,  635. 

Cambering,  Object  of,  463. 

Cambering  Side  Members  of  Frames, 
463. 

Cam  Case  Assembly,  Hupp,  154. 

Cam  Follower,  Mushroom  Type,  150. 

Cam  Follower,  Roller  Type,   150. 

Cam  for  Gradual  Closing,  149. 

Cam  for  Maximum  Valve  Opening, 
149. 

Cam  for  Quick  Lift,  149. 

Camshaft  Drive,  Silent  Chain,  156. 

Camshaft   Drive,   Spur   Gearing,    155. 

Camshaft  Driving  Methods,   155. 

Camshaft   Forms,    197. 

Camshafts,   Built  Up,    198. 

Camshafts,  One  Piece,   198. 

Cams,  Valve  Lifting,  149. 

Carbon  Filament  Bulb,  Current  Con- 
sumption of,  577. 


672 


Index 


Carburetion  Principles,  239. 

Carburetor  Adjustment  Methods,  256. 

Carburetor  Design,  Elements  of,  255. 

Carburetor   Requirements,   241. 

Carburetor,  Schebler  Model  "E,"  265. 

Carburetor,  Simple  Spray  Type,  249. 

Carburetors,  Breeze,  278. 

Carburetors,  Chapin,  271. 

Carburetors,  Excelsior,  272. 

Carburetors,  F.  I.  A.  T.  Double  Jet, 
281. 

Carburetors,  G  and  A,  276. 

Carburetors,  Holley,  268. 

Carburetors,  Holley  Kerosene,  288. 

Carburetors,  Kingston,   266. 

Carburetors,  Mercedes,  270. 

Carburetors,  Multiple-Nozzle,  278. 

Carburetors,   Peerless,   276. 

Carburetors,  Pierce,  273. 

Carburetors,  Saurer  Economy,  282. 

Carburetors,  Stromberg  Double  Jet, 
280. 

Carburetors,  Troubles  of,  648. 

Carburetors,   Zenith  Double  Jet,   289. 

Car  Lifting  Jacks,  601. 

Care  of  Finished  Parts,  601. 

Care  of  Front  Axles,  659. 

Care  of  Hands  when  Repairing,  666. 

Care  of  Miscellaneous  Chassis  Parts, 
660. 

Care  of  Shaft  Driving  Systems,  359. 

Care  of  Steering  Connections,  659. 

Care   of  Wet  Top,  665. 

Case  for  Tire  Repair  Material,  544. 

Casing  for  Driving  Chains,  497. 

Cast    Induction   Piping,   294. 

Cast-Iron  Head  Valve,  147. 

Cast  Metal   Automobile  Wheels,  512. 

Causes  for  Failure  of  Ignition  Sys- 
tems, 644. 

Causes  of  Blowing  and  Whistling,  651. 

Causes  of  Blowing  Back,   177. 

Causes  of  Body  Finish  Dulling,  662. 

Causes  of.  Difficult  Gear  Shifting,  657. 


Causes    of    Faulty    Magneto    Action, 

645. 

Causes  of  Friction  Disks  Slipping,  656. 
Causes   of  Grinding  Noise   in   Engine, 

651. 
Causes  of  Improperly  Timed    Ignition, 

643. 

Causes  of  Irregular  Ignition,  646. 
Causes   of  Knocking   Sounds,   651. 
Causes  of  Noisy  Power  Plant  Opera- 
tion, 650. 

Causes  of  No  Spark  at  Plugs,  644. 
Causes  of  Poor   Compression,  644. 
Causes  of  Poor  Fuel  Feed  from  Tank, 

647. 

Causes  of  Squeaking  Sounds,  651. 
Causes  of  Tire  Failure,  552. 
Caution,  a  Few  Words  of,  667. 
Center  of  Gravity,  Definition  of,  464. 
Center  of  Gravity,  Influence  on  Stabil- 
ity, 461. 

Chain  Protection  Cases,  497. 
Chains,  Anti-Skid  Forms,  528. 
Chains,  Non-Skid,  Application  of,  530. 
Chalmers  Starting  System,  566. 
Change      Speed     Gearing,     Combined 

with  Countershaft,  456. 
Change      Speed      Gearing,      Combined 

with  Power  Plant,  454. 
Change  Speed  Gearing,  Combined  with 

Rear  Axle,  457. 
Change  Speed  Gearing,  Face  Friction, 

431. 
Change  Speed  Gearing,  Functions  of, 

429. 
Change     Speed     Gearing,     Individual 

Clutch,  440. 
Change    Speed    Gearing,    Location    of, 

453. 

Change  Speed  Gearing,  Planetary,  435. 
Change     Speed     Gearing,    Progressive 

Sliding   Gear,   494. 
Change  Speed  Gearing,  Selective  Type, 

446. 


Index 


673 


Change  Speed  Gearing,  Silent  Chain 
Types,  441. 

Change  Speed  Gearing,  Sliding  Gear 
Types,  444. 

Change  Speed  Gearing,  Types  of,  430. 

Change  Speed  Gearing,  Utility  of,  429. 

Chapin  Carburetor  Construction,  271. 

Charging  the  Gasoline  Engine  Cylin- 
der, 81. 

Chassis,  Assembly  of,  51. 

Chassis,   Definition    of,    48. 

Chassis  Frame  Construction,  51. 

Chassis  Frame,  Use  of,  460. 

Chassis   Parts,   Care  of,   6GO. 

Chemical  Action,  Producing  Electric- 
ity by,  309. 

Chemistry  of  Combustion,  240. 

Circuits  of  Electric  Lighting  Systems, 
582. 

Circulating  Pumps,  Centrifugal,  for 
Water,  392. 

Circulating  Pumps,  Gear,  for  Water, 
392. 

Classes  of  Frame  Construction,  463. 

Classification  of  Motor  Car  Types. 
69. 

Cleaning  Mohair  Tops,  663. 

Closing  Exhaust  Valve,  178. 

Closing  Inlet  Valve,  180. 

Clutch   and   Brake   Interlock,   623. 

Clutch,  Function  of,  409. 

Clutch  Materials,  Frictional  Adhesion 
of,  411. 

Clutches,   Common   Defects   of,   653. 

Clutches,  Construction  of  Five-Plate, 
424. 

Clutches,  Construction  of  Multiple- 
Disk,  425. 

Clutches,  Construction  of  Three-Plate, 
421. 

Clutches,  Design  of  Cones,  416. 

Clutches,  Factors  Determining  Effi- 
ciency of,  420. 

Clutches,  Inverted  Cone  Type,  415. 


Clutches,  Metal  to  Metal  Cone  Type, 
417. 

Clutches,  Methods  of  Retaining  Fac- 
ing, 416. 

Clutches,  Oak  Tanned  Leather  Facing, 
412. 

Clutches,  Parts  of  Cone  Forms,  413. 

Clutches  of  Planetary  Gearsets,  428. 

Clutches,  Requirements  of,  410. 

Clutches,   "  Spinning "   Cones,  420. 

Clutches,  Use  of  Auxiliary  Friction 
Pads,  418. 

Clutches,  Use  of  Cone  Brake,  420. 

Clutches,  Value  of  Cork  Inserts,  412. 

Coil  for  Low  Tension  Ignition,  345. 

Combination  Gas  and  Electric  Lamps, 
580. 

Combination  Kerosene  and  Electric 
Lamps,  574. 

Combination  "  Live  "  and  "  Dead  " 
Rear  Axle,  490. 

Combination  Magneto  and  Battery  Ig- 
nition System,  365. 

Combination  of  Alcohol  and  Acety- 
lene, 236. 

Combination  Piston  and  Sleeve  Valves, 
161. 

Combination  Spark  Plug  and  Relief 
Cock,  336. 

Combined  Clutch  and  Brake  Pedal, 
Use  of,  629. 

Combustion  Chamber  Design,   126. 

Combustion,  Chemistry  of,  240. 

Common  Defects  in  Clutches,  653. 

Common  Troubles  of  Fuel  System,  647. 

Comparing  Automobile  and  Locomo- 
tive, 47. 

Comparing  Cannon  and  Gas  Engine, 
79. 

Compensating  Carburetor  Action,  255. 

Compensating  for  Varying  Atmos- 
pheric Conditions,  298. 

Compound   Spring  Forms,   473. 

Compounds,  Anti-Freezing,  634. 


674 


Index 


Compressed  Acetylene  Gas  Tank,  572. 
Compressed  Air  Starting  System,  564. 
Compressing  the  Gas  Charge,  81. 
Compression  Stroke,  Definition  of,  82. 
Concentric  Float  Design,  Advantages 

of,  256. 

Concentric  Piston  Ring  Design,  191. 
Concentric    Valve    Construction,    143. 
Conical  Rotary  Valves,  168. 
Cone    Clutch   Forms,   413. 
Cone    Clutch,   Metal   to   Metal   Type, 

417. 
Cone  Clutch  with  Adjustable  Springs, 

418. 
Cone  Clutches,  Care  of  Leather  Facing, 

654. 

Cone  Clutches,   Causes  of  Harsh   Ac- 
tion, 654. 

Cone  Clutches,  Causes  of  Slipping,  654. 
Cone  Clutches,  Causes  of  Spinning,  654. 
Connecting  Rod,  Ball  Bearing,  194. 
Connecting  Rod  Bearings,  193. 
Connecting  Rod  Forms,   193. 
Connecting  Rod,  Functions  of,  79. 
Connecting  Rod,   Hinged,    194. 
Connecting  Rod,  Marine  Type,  194. 
Connecting  Rods,  One  Piece,  194. 
Connecting  Rods,  Shapes  of  Sections, 

196. 
Connections    of    Parts    of    Induction 

Coils,  330. 
Constant  Level  Splash  Oiling  System, 

379. 

Constant   Speed    Dynamo,    319. 
Constructional  Details  of  Pistons,  186. 
Construction    of    Breeze     Carburetor, 

278. 
Construction    of    Chapin    Carburetor, 

271. 

Construction  of  Chassis  Frame,  51. 
Construction  of  Engine  Base,  214. 
Construction  of  Excelsior  Carburetor, 

272. 
Construction  of  Ford  Magneto,  321. 


Construction  of  Flywheels,  207. 
Construction  of  G  and  A  Carburetor, 

276. 
Construction    of    Gasoline    Strainers, 

286. 

Construction  of  Induction  Coil,  329. 
Construction  of  Induction  Piping,  294. 
Construction  of  Kingston  Carburetor, 

266. 

t    Construction  of  Knight  Motor,  99. 
Construction  of  Magneto  Generators, 

347. 
Construction  of  Mercedes  Carburetor, 

270. 
Construction         of          Multiple-Disk 

Clutches,  425. 
Construction    of   Peerless   Carburetor, 

276. 

Construction  of  Pierce  Carburetor,  273. 
Construction  of  Piston  Rings,  190. 
Construction  of  Schebler  Model  "  E " 

Vaporizer,  265. 

Construction  of  Storage  Battery,  314. 
Construction   of   Five-Plate  Clutches, 

424. 

Construction  of  Valve  Head,  147. 
Construction  of  Valves,  146. 
Construction  of  Windshields,  585. 
Construction,  Trend  of,  40. 
Control  System  of  Buick  Car,  624. 
Control  System  of  Carter  Car,  614. 
Control  System  of  Ford  Car,  618. 
Control  System  of  Jackson  Car,  630. 
Control  System  of  Knox  Car,  630. 
Control  System  of  Liberty-Brush  Car. 

620. 

Control  System  of  Maxwell  Car,  616 
Control  System  of  Mitchell  Car,  630. 
Control  System  of  Pierce-Arrow  Car. 

623. 

Control  System  of  Reo  Car,  628. 
Controlling  Car  with  Friction  Trans- 
mission, 614. 
Controlling  Planetary  Gears,  616. 


Index 


675 


Conventional  Frame  Type,  460. 

Conventional  Rear  Axle  Transmis- 
sion, 459. 

Cooling  Systems,  Air,  390. 

Cooling  Systems,  Defects  of,  649. 

Cooling  Systems  in  Use,   389. 

Cooling  Systems,  Reason  for  Use, 
388. 

Cooling  Systems,  Thefmo-Syphon,  393. 

Cork  Float  Features,  258. 

Cork  Inserts,  Value  in  Clutches,  412. 

Cote  Two-Cycle  Motor,  220. 

Countershaft  and  Change  Speed  Gear- 
ing, 456,  457. 

Crankcase,  Barrel  Type,  215. 

Crankcase  Parts,  Accessibility  of,  216. 

Crankcase,  Two-Piece,  215. 

Crankshaft,  Built  Up,   200. 

Crankshaft    Construction,    199. 

Crankshaft  Design,  Influence  of  Cyl- 
inders on,  124. 

Crankshaft,  Functions  of,  80. 

Crankshaft,  Two  Bearing  Four-Cylin- 
der, 203. 

Crankshaft,  Two-Throw,  202. 

Crankshaft  Types  Outlined,  199. 

Crankshafts,  Ball  Bearing,  205. 

Crankshafts,  Five  Bearing,  203. 

Crankshafts,  Offset,  131. 

Crankshafts,  Three  Bearing,  203. 

Current  Consumption  of  Carbon  Fila- 
ment, 577. 

Current  Consumption,  Tungsten  Fila- 
ment, 577. 

Current  Production  by  Chemical  Ac- 
tion, 309. 

Current  Strength  from  Storage  Bat- 
tery, 316. 

Cushion  Tire,   Combination,   536. 

Cushion  Tire,  Dual  Tread,  535. 

Cushion  Tire,  Sectional,  536. 

Cushion  Tires,  534. 

Cut-out  Valve,  Utility  of,  305. 

Cycle  of  Gasoline  Engine,  82, 


Cylinder    Casting    Methods    Influence 

Crankshaft  Design,  124. 
Cylinder  Cooling  by  Water,  389. 
Cylinder  Cooling,   Theory  of,   389. 
Cylinder  Construction  Methods,  119. 
Cylinder,  Knox  Individual,  141. 
Cylinder,  L  Head  Type,  140. 
Cylinder,  Lubricants  for,  372. 
Cylinder,  Separable  Head  Types,  123. 
Cylinder,   T   Head   Type,   137. 
Cylinder,    Valve   in    the    Head    Type, 

137. 

Cylinders  Cast  En-bloc,  121. 
Cylinders  Cast  Individually,  Features 

of,  121. 
Cylinders  Cast  in  Pairs,  Features  of, 

121. 


Darracq,    Rotary    Distributor    Valve, 

173. 

"  Dead,"  Rear  Axle,  487. 
Defects  in  Sliding  Gear  Transmission, 

657. 

Defects  in  Spark  Plugs,  646. 
Defects  in  Timers  or  Distributors,  646. 
Defects  in  Vibrator  Coils,  647. 
Defects  in   Wiring,   647. 
Defects  of  Cooling  Systems,  641. 
Defects  of  Oiling  Systems,  649. 
Defects     of    Planetary    Transmission, 

656. 

Defining  L  Head  Cylinder  Design,  145. 
Definition  of  Amperage,  312. 
Definition  of  Center  of  Gravity,  461. 
Definition  of  Chassis,  48. 
Definition  of  Compression  Stroke,  82. 
Definition  of  Exhaust  Stroke,  82. 
Definition  of  Friction,   369. 
Definition  of  Intake  Stroke,  82. 
Definition  of  Piston  Speed,  129. 
Definition  of  Power  Stroke,  82, 
Definition  of  Voltage,  312. 


676 


Index 


Definition  of  Wattage,  312. 
Deflector,   Location  of,  187. 
Demountable  Rim  Forms,  531. 
Denatured  Alcohol  as  Fuel,  236. 
Denatured  Alcohol,  Use  as  Anti-freez- 
ing Compound,  636. 
Derangements     of    Friction    Gearing, 

656. 

Derivation  of  Lubricants,  371. 
Describing       Conventional       Exhaust 

Valve   Operation,    101. 
Describing    Conventional   Inlet    Valve 

Operation,  101. 

Description  of  Amplex  Motor,  218. 
Description    of    Knight    Sleeve   Valve 

Operation,   103. 

Design  of  Air  Cooled  Engines,  398. 
Design  of  Clutch  Cones,  416. 
Design  of  Combustion  Chamber,  126. 
Design    of    Concentric    Piston     Ring, 

191. 

Design  of  Eccentric  Piston  Ring,  191. 
Design  of  Float  Bowl,  258. 
Design  of  Frames,  460. 
Design  of  French  Rotary  Valves,  167. 
Design  of  Leaf  Springs,  467. 
Design   of  L   Head   Cylinder,   145. 
Design  of  Oscillating  Wristpin,  190. 
Design  of  Spark  Plugs,  332. 
Design  of  Valves,  145. 
Determining  Power  Needed  to  Propel 

Car,  68. 
Development  of  Float  Feed  Vaporizers, 

252. 

Devices  for  Supplying  Lubricant,  374. 
Diagrams,   Valve   Timing,   182. 
Diameter  Limits   of   Fly-wheels,   210. 
Differential  Gearing,  Action  of,  491. 
Differential  Gear,  'Purpose  of,  490. 
Differential  Piston  Design,  187. 
Differential  Piston  Two-Cycle  Engine, 

111. 

Direct  Air  Cooling  System,  397. 
Direction,  of  Air  Currents,  65. 


Disadvantages  of  Chemical  Current 
Producers,  317. 

Disadvantages  of  Gravity  Oilers,  376. 

Disadvantages  of  Simple  Battery,  313. 

Disadvantages  of  Single  Cylinder  Mo- 
tors, 84. 

Disadvantages  of  Spring  Wheels,  517. 

Disadvantages  of  Two-Cycle  Engines, 
112. 

Disadvantages  of  Wire  Wheels,  513. 

Disk  Rotary  Valves,  166. 

Disposition  of  Exhaust  Gases,  300. 

Distillates  of  Petroleum,  232. 

Distributor,  Secondary,  Action  of,  324. 

Division  of  Mechanism  in  Gro.ups,  40. 

Double  Cone   Rotary  Valves,   167. 

Double  Reduction  Gearing  in  Rear 
Axles,  496. 

Drag  Link,  Functions  of,  476. 

Driving  Chains,  Adjustment  of,  658. 

Driving  Chains,  Faults  of,  657. 

Driving  Chains,  Proper  Method  of 
Lubricating,  658. 

Driving  Instructions,  General,  631. 

Driving  Magneto  Armatures,  361. 

Drop  Frame  Type,  464. 

Dry  Battery  Action,  310. 

Dry  Battery  for  Current  Supply,  310. 

Drum  Type  Rotary  Valves,  166. 

Dual  Cylinder  Castings,  121. 

Dual  Ignition  Systems,  366. 

Dual  Tread  Cushion  Tire,  535. 

Dust  Disturbance  and  Body  Design,  62. 

Dynamo,  Constant  Speed  Type,  319. 

Dynamo  Electric  Machines,  317. 

Dynamo  Speed  Governor,  Action  of, 
319. 


E 


Early  Methods  of  Gas  Ignition,  307. 
Early   Vaporizer  Forms,   247. 
Eccentric  Bushings  in  Steering  Gears, 

478. 


Index 


677 


Eccentric  Piston  Ring  Design.  191. 
Economy    of    Fuel,    Effect    of    Spark 

Lever,  612. 

Edison  Screw  Base  Lamp,  577. 
Kdi-S\van  Bulb  Retention,  577. 
Efficiency  of  Power  Transmission 

Systems,  406. 
Efficiency    of    Shaft   Driving    Method, 

486. 

Efficiency  of  Side  Chain  Drive,  484. 
Efficiency  of  Single  Chain  Drive,  484. 
Efficiency  of  Worm  Gearing,  495. 
Eight-Cylinder  V  Motor,  229. 
Electrical  Alarms,  588. 
Electrical  Ignition  Means,  308. 
Electrically  Welded  Valve,  147. 
Electric  Car  Features,  37. 
Electric  Cell,  Dry  Type,  310. 
Electric  Cell,  Parts  of,  309. 
Electric  Cell,  Simple  Primary,  309. 
Electric  Headlight  Design,  579. 
Electric  Ignition  Systems,  Elements  of, 

3u8. 
Electric     Lamps,     Combination     Gas, 

580. 
Electric    Lamps,    Combination    Type, 

574. 

Electric  Lighting  Battery,  573. 
Electric  Lighting  Fixtures,  578. 
Electric  Lighting  System,  573. 
Electric  Lighting  System,  Fixtures  for, 

578. 
Electric    Lighting    System,    Headlight 

for,  579. 
Electric   Lighting   System,   Six  Lamp, 

582. 
Electric  Lighting  System,  Three  Lamp, 

582. 
Electric  Lighting  Systems,  Circuits  for, 

582. 

Electric  Spark  for  Ignition,  308. 
Electric  Starting  System,  567. 
Electrolytic  Action  of  Alkaline  Solu- 
tions, 634. 


Elements  of  Carburetor  Design,  255. 

Elements  of  Electric  Ignition  Systems, 
308. 

Elements  of  Typical  Water  Cooling 
Group,  391. 

Elliot  Type  Steering  Knuckle,  483. 

En-Bloc  Cylinder  Castings,  121. 

Engine  Base  Construction,  214. 

Engine  Cylinder,  Functions  of,  79. 

Engine,  Darracq  Rotary  Valve,  173. 

Engine  Design,  Influence  of  Cylinder 
Construction  of,  133. 

Engine,  Eight  Cylinder  Type,  229. 

Engine,  Hewitt  Piston  Valve,  173. 

Engine,  Itala  Rotary  Valve,  163. 

Engine,  Mead  Rotary  Valve,  166. 

Engine,  Reynolds  Rotary  Valve,  166. 

Engine  Starter  Forms,  561. 

Engine,    Three-Port,    Two-Cycle,    110. 

Engine,  Two-Cycle  Principles,  105. 

Engine,   Two-Port,  Two-Cycle,  106. 

Engines  for  Automobiles,  Forms  of, 
76. 

Engines,  Instructions  for  Valve  Tim- 
ing, 185. 

Engines,  Miesse  Valveless,   161. 

Equipment  for  Motor  Car,  560. 

Essential  Elements  of  Gas  Engine, 
80. 

Excelsior  Carburetor  Construction, 
272. 

Excessive  Spark  Advance,  Effect  of, 
611. 

Exhaust  Gases,  Disposition  of,  300. 

Exhaust  Manifold  with  Ejector  Ac- 
tion, 304. 

Fxhaust  Operated  Alarms,  588. 

Exhaust  Stroke,  Definition  of,  82. 

Exhaust  Valve  Closing,   178. 

Exhaust  Valve  Lead  Given,  178. 

Exhaust  Valve  Operation,  Description 
of,  101. 

Exhausting  the  Burnt  Gas,  82. 

Exploding  the  Gas  Charge,  81. 


678 


Index    • 


F 

Face  Friction  Gearing,  431. 

Factors  Determining  Efficiency  of  Cone 
Clutches,  420. 

Factors  Determining  Flywheel  Diam- 
eter, 210. 

Factors  Determining  Flywheel  Weight, 
207. 

Fan  Blade  Spoke  Flywheels,  208. 

Fans  for  Circulating  Air,  400. 

Fans  for  Cooling  Systems,  396. 

Faults  of  Chain  Driving  Systems,  657. 

Faulty  Magneto  Action,  Causes  of, 
645. 

Features   of  Cork   Floats,  258. 

Features  of  Cylinders  Cast  in  Pairs, 
121. 

Features  of  Electric  Cars,  37. 

Features  of  Four-Cylinder  Motor,  94. 

Features  of  Individually  Cast  Cylin- 
ders, 121. 

Features  of  Holley  Carburetor,  268. 

Features  of  Hollow  Metal  Floats,  258. 

Features  of  Knight  Motor,  97. 

Features  of  Knox  Cylinder  Head,  141. 

Features  of  Low  Tension  Ignition  Sys- 
tem, 343. 

Features  of  Multiple-Disk  Clutches, 
425. 

Features  of  Two-Cylinder  Motor,  93. 

Features  of  Unit  Power  Plants,  113. 

Features  of  Valve  Location,  136. 

F.  I.  A.  T.  Double  Jet  Carburetor, 
281. 

Fiber  Friction  Ring,  -Life  of,  656. 

Figuring  Frontal  Area  of  Auto,  63. 

Fire  Inflation  Gauges,  552. 

Five  Bearing  Four-Cylinder  Crank- 
shafts, 203. 

Five  Plate  Clutch  Construction,  424. 

Fixtures  for  Electric  Lighting,  578. 

Fixed  Winding  Type  Magneto,  356. 

Flat  Seat  Valve,  146. 


Flexibility  of  Automobile  Power 
Plants,  609. 

Float  Bowl   Design,   258. 

Float  Feed  Carburetor  Action,  254. 

Float  Feed  Vaporizers,  Development 
of,  252. 

Floating  Type  Rear  Axle,  487. 

Floats,  Cork,  258. 

Floats,  Hollow  Metal,  258. 

Flywheel,  Blower  Type,   402. 

Flywheel   Construction,  207. 

Flywheel,  Function  of,  207. 

Flywheel,   Function  of,  80,  207. 

Flywheel  Retention  by  Flange  and 
Bolts,  211. 

Flywheel  Retention  by  Gib  Key,  211. 

Flywheel  Retention  by  Taper  and 
Key,  211. 

Flywheel  Weight,  Factors  Determin- 
ing, 207. 

Flywheels,  Factors  Determining  Diam- 
eter, 210. 

Flywheels,  Interpretation  of  Marks, 
184. 

Flywheels,  Method  of  Marking  Rims, 

'    213. 

Flywheels,  Retention  of,  210. 

Flywheels  with  Fan  Blade  Spokes,  208. 

Forced  Circulation  System,  389. 

Ford  Magneto,  Action  of,  321. 

Ford  Model  "  T,"  Control  System  of, 
618. 

Forms  of  Auxiliary  Air  Valves,  261. 

Forms  of  Camshafts,  197. 

Forms  of  Cone  Clutches,  413. 

Forms  of  Connecting  Rods,  193. 

Forms  of  Electrical  Ignition,  308. 

Forms  of  Engines  Commonly  Used,  76. 

Forms  of  Flywheels,  207. 

Forms   of   Front  Axles,  481. 

Forms  of  Gasoline  Spray  Nozzles,  260. 

Forms  of  Induction  Manifolds,  294. 

Forms  of  Jacks,  601. 

Forms  of  Mixing  Chambers,  256. 


Index 


679 


Forms  of  Mufflers,  302. 

Forms  of  Oil  Pumps,  377. 

Four-Cycle  Engine  Action,  78. 

Four-Cycle  Power  Plants,  225. 

Four-Cylinder  Engine  Ignition  Sys- 
tem, 341. 

Four-Cylinder  Induction  Manifolds, 
290. 

Four-Cylinder  Motor,  Sequence  of 
Cycles,  88. 

Four-Cylinder  Vertical  Motor  Fea- 
tures, 94. 

Four  Speed  Selective,  Gearset  Design. 
451. 

Frame  Construction,  Classes  of,  463. 

Frame  Construction,  Materials  Used, 
4G2. 

Frame  Construction,  Pressed  Steel, 
463. 

Frame  Construction,  Steel  Tubing, 
462. 

Frame  Construction,  Wood,  462. 

Frame  Design,  460. 

Frame   Suspension   Means,   465. 

Frame  Types,  Conventional,  460. 

Frame   Types,  Underslung,   461. 

Frame,  Utility  of,  460. 

Frames,  Drop  Type,  464. 

Frames,  Methods  of  Spring  Attach- 
ment, 471. 

Frames,    Upswept    Type,    464. 

Freezing  Point  of  Alcohol  Solutions, 
636. 

Freezing  Points  of  Calcium  Chloride 
Solutions,  635. 

French  Rotary  Valve  Design,  167. 

Frictional  Adhesion  of  Clutch  Mate- 
rials, 411. 

Friction  Clutch  Operation,  411. 

Friction,  Definition  of,  369. 

Friction  Gearing,  Defects   of,   656. 

Friction  Pedal,  Operation  of,  616. 

Friction  Transmission  for  Shaft  Drive, 
433. 


Friction    Transmission,    Operation    of, 

431. 
Friction     Transmission,     Side     Chain 

Drive,  433. 
Friction    Transmission,    Single    Chain 

Drive,  433. 
Frontal  Area  of  Automobiles,  Figuring 

of,  63. 

Front  Axle  Forms,  481. 
Front  Axle,  I  Beam,  481. 
Front  Axle,  Tubular,  481. 
Front  Axles,  Care  of,  659. 
Front  End  Suspension,  468. 
Front  Hub  Bearings,  483. 
Front  Hub  Construction,  482. 
Front  Wheel  Bearings,  Adjustment  ofj 

659. 

Front   Wheel   Brakes,   505. 
Front    Wheel    Brakes,    Disadvantages 

of,  508. 
Front    Wheel    Brakes,    Operation    of, 

507. 
Fuel   Consumption   of  Knight  Motor, 

105. 
Fuel  ^System,    Common    Troubles   of, 

647. 

Fuels   for  Engines,  Alcohol,   234. 
Fuels  for  Engines,  Benzol,  233. 
Fuels  for  Engines,  Gasoline,  232. 
Fuels  for  Engines,  Kerosene,  234. 
Fuels  for  Engines,  Solid  Gasoline,  238. 
Full  Elliptic  Springs,  467. 
Function  of  Clutch,  409. 
Function  of  Flywheel,  80,  207. 
Function  of  Spark  Plug,  80. 
Function  of  Wristpin,  188. 
Functions  of   Change  Speed  Gearing, 

429.  . 

Functions  of  Connecting  Eod,  79. 
Functions  of  Crankshaft,  79. 
Functions  of  Drag  Link,  476. 
Functions  of  Engine  Cylinder,  79. 
Functions  of  Motor  Car  Parts,  47,  49. 
Functions  of  Piston,  79. 


680 


Index 


Functions  of  Piston  Rings,  190. 
Functions  of  Shock  Absorbers,  585. 
Functions   of  Spark  Gap,   337. 
Functions  of  Spring  Shackles,  468. 
Functions   of  Timer   and   Distributor, 

321. 

Functions  of  Tie  Bar,  475. 
Functions      of     Two-Cycle     Cylinder 

Ports,    108. 


G 


G    and    A    Carburetor    Construction, 

276. 
Gas  Charge  in  Cylinder,  Compression 

of,  81. 
Gas  Charge  in  Cylinder,  Exhausting, 

82. 
Gas  Charge  in  Cylinder,  Explosion  of, 

81. 
Gas  Charge  in   Cylinder,  Pressure  of, 

81. 
Gas    Engine   and    Cannon    Compared, 

79. 
Gas    Engine,    Essential    Elements    of, 

80. 

Gas  Mixture  Supply  Regulation,  262. 
Gas  Supply  Regulation  by  Governor, 

263. 

Gasoline  Car,  Advantages  of,  37. 
Gasoline  Engine,  Cycle  of,  82. 
Gasoline    Engine    Cylinder,    Charging 

the,  81. 

Gasoline  Engine  Ignition  Systems,  307. 
Gasoline  Engine  Starters,  561. 
Gasoline    Strainers,    Construction    of, 

286. 
Gasoline     Strainers,     Installation     of, 

280. 

Gasoline  Strainers,  Utility  of,  286. 
Gasoline  Supply  by  Gravity  Feed,  244. 
Gasoline    Supply    by    Pressure    Feed, 

244. 


Gasoline  Supply  by  Pump,  246. 
Gauges  for  Tire  Inflation,  552. 
Gearing,  Bevel  and  Spur  Combination, 

499. 

Gearing,  Double  Reduction  Axle,  496. 
Gearing,  Face  Friction,  431. 
Gearing  for  Camshaft  Drive,  155. 
Gear  Pump,  Oil,  377. 
Gear    Shifting,    Cause    of    Defects   in, 

657. 

Gear  Shifting  on  Knox  Cars,  625. 
Gear    Shifting    on    Locomobile    Cars, 

625. 

Gear  Shifting  on  Peerless  Cars,  624. 
General  Driving  Instructions,  631. 
General    Supplies   for   Repairing,   597. 
Generator  for  Acetylene  Gas,  570. 
Glycerine,    Use    of,    as    Anti -Freezing 

Compound,  635. 
Gravity  Feed  Systems,  244. 
Gravity  Oilers,  Disadvantages  of,  376. 
Grinding  Noises  in  Engine,  Causes  of, 

651. 


II 


Hand    Wheel    Movement   in    Steering 

Gears,  479. 
Heat    Loss    Through   Exhaust    Valve, 

388. 
Heat    Loss    Through    Water    Jacket, 

388. 

Helical  Coil  Spring  Suspension,  473. 
Hewitt  Piston  Valve  Motor,  173. 
Hickory,  Use  of,  in  Wheels,  512. 
High  Tension  Ignition  System,  341. 
Hinged  Connecting  Rod,  194. 
Hints  for  Tire  Manipulation,  545. 
Holley   Carburetor  Features,  268. 
Holley    Hot    and    Cold    Air    Shutter, 

298. 

Holley   Kerosene    Carburetor,   288. 
Hollow  Metal  Float  Features,  258. 


Index 


681 


Horizontal  Single-Cylinder  Motor,  83. 

Horizontally  Split  Two  Piece  Crank- 
case,  215. 

How  Automobiles  are  Steered,  473. 

How  Gasoline  Engine  Works,  78. 

How    Supplies    are    Carried,    603. 

How  to  Keep  Hands  Soft,  666. 

How  to  Prevent  "  Kick  Back,"  608. 

Hubs,  Construction  for  Front  Wheels, 
482. 

Hupp  Cam  Case  Assembly,  154. 

Hydraulic  Valve  Operation  Means, 
151. 


I  Beam  Front  Axle,  481. 

Igniter  Plate  for  Low  Tension  Igni- 
tion, 344. 

Igniter  Plate,  Operation  of,  345. 

Ignition  by  Electric  Spark,  308. 

Ignition  by  Flame,  307. 

Ignition  by  Hot  Head,  308. 

Ignition  by  Incandescent  Tube,  307. 

Ignition  Magneto,  Parts  and  Func- 
tions, 350. 

Ignition  Magneto,  Spacing  of  Contacts, 
349. 

Ignition  Magnetos,  Forms  of,  359. 

Ignition  Magnetos,  Installation  of, 
360. 

Ignition  Magnetos,  Methods  of  Reten- 
tion, 361. 

Ignition  Magnetos,  Speed  of  Armature, 
349. 

Ignition  Magnetos,  Systems  Used,  350. 

Ignition  out  of  Time,  Causes  of,  643. 

Ignition  Starters,  563. 

Ignition  System,  Causes  of  Failure, 
649. 

Ignition  Systems,  Battery,  341. 

Ignition  Systems,  Distributor,  342. 

Ignition  Systems,  Early  Types,  307. 

Ignition  Systems,  Gasoline  Engine,  307. 


Ignition  Systems,  Magneto,  350. 
Ignition  Systems,  Six-Cylinder,  343. 
Ignition,  Time  of,  181. 
Impediments    to    Water    Circulation, 

650. 
Incandescent  Bulbs  for  Electric  Lamps, 

576. 

Indirect  Valve  Operation  Method,  150. 
Individually  Cast  Cylinder,  Features, 

121. 

Individual  Clutch  Change  Speed  Gear- 
ing, 440. 
Individual  'Clutch  Gearset  with  Silent 

Chains,    441. 

Individual  Pump  Oiling  Method,  385. 
Induction  Coil  Action,  Theory  of,  329. 
Induction  Coil,  Connections  of  Parts, 

330. 

Induction  Coil  Construction,  329. 
Induction  Coil,  Typical  Form,  329. 
Induction  Manifold  for  Kerosene,  290. 
Induction  Manifold  Forms,  294. 
Induction    Manifolds,    Four-Cylinder, 

296. 
Induction      Manifolds,      Six- Cylinder, 

297. 

Jnduction  Piping,  Built  up,  294. 
Induction  Piping,  Cast  Forms,  294. 
Induction     Piping,     Construction     of, 

294. 
Influence  of  Cylinder  Construction  on 

Engine  Design,  133. 
Inlet  Valve  Closing,  180. 
Inlet  Valve  Opening,  179. 
Inlet  Valve  Operation,  Description  of, 

101. 

Installation  of  Gasoline  Strainers,  286. 
Installation  of  Magnetos,  360. 
Installation  of  Power  Plants,  113. 
Installation   of  Spark   Plugs,   335. 
Instruction  for  Valve  Timing,  176. 
Insulation  for  Induction  Coils,  330. 
Insulation  for  Secondary  Distributor, 

324. 


682 


Index 


Insulation  for  Timer  Contacts,  324. 
Insulation  Materials  for  Plugs,  334. 
Insulation,    Mica     for    Spark    Plugs, 

333. 
Insulation,  Porcelain  for  Spark  Plugs, 

333. 

Intake    Stroke,    Definition   of,    82. 
Internal   Brake,   Cam   Expanded,  501. 
Internal  Brake,  Toggle  Expanded,  501. 
Interpretation  of  Flywheel  Marks,  184. 
Inverted    Cone    Clutch    Construction, 

415. 

Irregular  Ignition,  Causes  of,  046. 
Irreversible  Steering  Gears,  475. 
Itala  Rotary  Valve  Motor,  163. 


Jack,  Forms  of,  601. 
Jacks,  Car  Lifting,  601. 
Jackson  Cars,  Control  System  of,  630. 
Janney-Steinmetz  Air  Starter,  565. 
Joining  Cells  in  Multiple,  312. 
Joining  Cells  in  Multiple  Series,  312. 
Joining  Cells  in  Series,  312. 
Joints  in  Piston  Rings,  191. 
Judging  Combustion  by  Color  of  Ex- 
haust, 648. 


Kerosene  as  Engine  Fuel,  234. 
Kerosene  Supply  by  Injection,  291. 
"  Kick  Back,"  How  to  Prevent,   608. 
Kingston      Carburetor     Construction, 

266. 
Knight  Motor,  Fuel  Consumption  of, 

105. 

Knight  Motor  Test  Results,  104. 
Knight  Sleeve  Valves,  99,  160. 
Knight   Sleeve   Valves,   Operation   of, 

103. 


Knight   Slide  Valve  Motor   Feature's. 

97. 

Knight  Sliding  Sleeve   Valves,   161. 
Knocking  Sounds,  Causes  of,  651. 
Knox  Cars,  Control  System  of,  630. 
Knox  Cars,  Gear  Shifting  Method,  625. 


L  Head  Cylinder  Construction,  140. 

L  Head  Cylinder  Design,   145. 

Laminated  Leaf  Springs,  466. 

Laminated  Wood  Frames,  462. 

Lamps  for  Acetylene  Lighting,  572. 

Lamps  for  Electric  Lighting,  574. 

Lanchester  Wick  Carburetor,  257. 

Lead  Given  Exhaust  Valve,  178. 

Leaf   Springs,   Design  of,   467. 

Leather  Auto  Tops,  Method  of  Treat- 
ing, 664. 

Leather  Clutch  Facings,  Care  of, 
654. 

Leather,  Oak  Tanned  for  Clutches, 
412. 

Leather,  Retaining  Facing  of  Cone, 
416. 

Leather,  Retention  by  Rivets,  416. 

Leather,  Retention  by  T  Bolts,  416. 

Leather  Top  Treatment,  Preparations 
for,  664. 

Left  Hand  Control,  Advantages  of, 
627. 

Legros  Two-Cycle  Motor,  220. 

Liberty-Brush  Runabout,  Control  Sys- 
tem of,  620. 

Life  of  Fiber  Friction   Ring,  650. 

Lighting  System,  Acetylene  Gas,  570. 

Lighting  Systems,  Electric,  573. 

Lighting  Systems,  Motor  Car,  569. 

Liquid  Fuel  Application,  231. 

Liquid  Fuel  Storage,  244. 

"Live"  Rear  Axles,  487. 

Locating  Power  Plant  Troubles.  641. 


Index 


683 


Location    of    Change    Speed    Gearing, 

453. 

Location  of  Deflector,  187. 
Location  of  Motor  Car  Parts,  47,  49. 
Locomobile      Cars,       Gear      Shifting 

Method,  625. 

Long  Stroke   Advantages,   126. 
Loosening  Clincher  Shoes,  546. 
Low  Tension  Igniter  Plate,  344. 
Low  Tension  Ignition,   Coil  for,  345. 
Low  Tension  Ignition,  Disadvantages 

of,  346. 

Low  Tension  Ignition  System,  343. 
Low  Tension  Ignition  Wiring  Scheme, 

345. 

Lubricants,  Cylinder,  372. 
Lubricants,  Derivation  of,  371. 
Lubricants,  Devices  for  Supplying,  374. 
Lubricants,  Fire  Test  of  Cylinder  Oil, 

373. 
Lubricants,  Flash  Test  of  Cylinder  Oil, 

373. 

Lubricants,  Fluid,  371. 
Lubricants,  Oleo-Naphthas,  371. 
Lubricants,  Organic,  371. 
Lubricants,  Qualities  Needed,  370. 
Lubricants,  Semi-Solid,  371. 
Lubricants,  Solid,  371. 
Lubricating  System,  Winter  Care  of, 

637. 

Lubrication,  by  Centrifugal  Force,  387. 
Lubrication,  Gravity  Method,  379. 
Lubrication,  Individual  Pump  System, 

385. 

Lubrication,  Mechanical,  377. 
Lubrication  of  Driving  Chains,  658. 
Lubrication  of  Mechanism,  Reason  for, 

368. 

Lubrication,  Positive  Systems,  377. 
Lubrication,  Pressure  Feed,  384. 
Lubrication,  Splash  System,  379. 
Lubrication,  Theory  of,  370. 
Lubricators,    Individual    Pump    Type, 

385. 


Lubricators,  Mechanical,  377. 
Lubricators,  Sight  Feed  Gravity  Cups. 

374. 
Lubricators,  Types  of;  374. 


M 


Magneto  Armatures,  Methods  of  Driv- 
ing, 361. 

Magneto-Generator  Construction,  347. 
Magneto  Ignition,  Double  System,  364. 
Magneto  Ignition,  Dual  System,  366. 
Magneto  Ignition  Systems,  350. 
Magnetos,    Wiring   of   High    Tension, 

352. 
Magnetos,     Wiring     of     Transformer 

Type,  354. 

Magneto  with  Fixed  Winding,  356. 
Maintenance  of  Body  and  Upholstery, 

661. 

Manifolds  for  Oil  Distribution,  382. 
Marine  Type  Connecting  Rod,   194. 
Materials  for  Frame  Construction,  462. 
Materials,  Metallic,  for  Clutches,  411. 
Materials  Used  in  Tire  Construction, 

519. 
Maxwell    "  AA,"    Control    System    of, 

616. 

Mead  Rotary  Valves,  166. 
Mechanically  Fastened  Tire  Tools,  547. 
Mechanical  Oiling  Methods,  377. 
Mechanical  Production  of  Electricity, 

317. 

Mechanical  Starters,  562. 
Mechanism,  Division  in  Groups,  46. 
Mercedes      Carburetor      Construction, 

270. 

Mercedes  Steering  Knuckle,  483. 
Metal  Automobile  Wheel  Types,  512. 
Metal,  Cast  Automobile  Wheels,  512. 
Metallic  Materials  Used  in   Clutches. 

411. 
Method  of  Cone  Clutch  Operation,  414. 


684 


Index 


Method  of  Indirect  Valve  Operation, 
150. 

Method  of  Leather  Retention,  Cone 
Clutches,  416. 

Method  of  Marking  Flywheel  Rim, 
213. 

Method  of  Using  Starting  Crank, 
608. 

Methods  of  Air  Cooling,  390. 

Methods  of  Constructing  Crankshafts, 
199. 

Methods  of  Cylinder  Construction, 
119. 

Methods  of  Driving  Cam  Shaft,  155. 

Methods  of  Flywheel  Retention,  210. 

Methods  of  Oil  Distribution,  378. 

Methods  of  Valve  Operation,   150. 

Methods  of  Valve   Placing,   137. 

Methods  of  Wiring  Primary  Cells, 
311. 

Methods  of  Wristpin  Retention,  188. 

Mica   Insulated   Plug,   332. 

Miscellaneous  Chassis  Parts,  Care  of, 
660. 

Miscellaneous    Supplies,    602. 

Mitchell  Car,  Control  System  of,  630. 

Mixing  Chamber  Forms,  256. 

Mohair  Auto  Tops,  Method  of  Clean- 
ing, 663. 

Motor   Car   Alarms,   588. 

Motor  Car  Alarms,  Electrical,   588. 

Motor  Car  Alarms,  Exhaust  Oper- 
ated, 588. 

Motor  Car  Brakes,  Adjustment  of, 
660. 

Motor  Car  Equipment,  560. 

Motor  Car  Lighting  Systems,  569. 

Motor  Car  Maintenance,  Supplies  for, 
599. 

Motor  Car  Parts,  Functions  of,  47,  49. 

Motor  Car  Parts,  Location  of,  47,  49. 

Motor  Car  Principles,  43. 

Motor  Car  Repairs,  Tools  for,  594. 

Motor  Car  Types,  Classification  of,  69. 


Motor    Control    Levers,    Mounting   on 

Steering  Gear,  481. 
Motor  Control    System,  Typical,   609. 
Motor  Installation,   Under   Seat,   117. 
Motor,  Knight  Slide  Valve,  97. 
Motor  Speed  Regulation,  610. 
Muffler  Forms,  302. 
Mufflers,  Water-cooled,  303. 
Multiple  Connection  for  Cells,  312. 
Multiple-Disk    Brakes,    504. 
Multiple-Disk  Clutches,  Care  of,  654. 
Multiple-Disk   Clutches,    Features    of, 

425. 

Multiple-Nozzle  Carburetors,  278. 
Multiple-Series   Connections  for  Cells, 

312. 
Mushroom  Cam  Follower,  150. 


N 


Natural    Circulation   System,   389. 
Necessary    Elements    of    Automobiles, 

44. 

"Never  Miss"   Starting  System,  565. 
Noisy    Action    of   Planetary   Gearing, 

656. 

Noisy  Power  Plant,  Causes  of,  050. 
Number  of  Speeds  in  Sliding  Gearsets, 

447. 


O 


Oak  Tanned  Leather  for  Clutches,  412. 

Obtaining  Gasoline  for  Priming  Cylin- 
ders, 638. 

Obtaining  Varying  Car  Speeds  with 
Friction  Gears,  614. 

Off-Set  Crankshafts,    131. 

Off-Set  Cylinder  Advantages,  130. 

Oil  Distribution  by  Manifolds,  382. 

Oil  Distribution  by  Pressure,  384. 

Oil  Distribution   Methods,  378. 

Oil  Pump   Forms,   377. 


Index 


685 


Oil  Spots  on  Clothing,  Removal  of, 
639. 

Oil  Spots,  Preparations  for  Removing, 
640. 

Oiling  Devices,  Requirements  of,  374. 

Oiling  Methods,  Individual  Pumps, 
385. 

Oiling   Methods,   Mechanical,   377. 

Oiling,   Suggestions   for,   632. 

Oiling  Systems,  Constant  Level  Splash, 
379. 

Oiling  Systems,  Defects  of,  649. 

Oils,  Derivation  and  Use,  371. 

Oils  for  Cooling  Systems,  637. 

One  Piece  Camshafts,  198. 

One  Piece  Connecting  Rod,  194. 

One  Piece  Steel  Valve,  147. 

Opening  Inlet  Valve,  179. 

Operating  Front  Wheel  Brakes,  507. 

Operating  Means  for  Ring  Valves,  171. 

Operating  Sliding  Gearsets,  623. 

Operation  of  Cone   Clutches,  414. 

Operation  of  Cooling  Group,  391. 

Operation  of  Differential  Piston  En- 
gine, 111. 

Operation  of  Friction  Clutches,  411. 

Operation  of  Friction  Transmission, 
431. 

Operation  of  Igniter  Plate,  345. 

Operation  of  Individual  Clutch  Gear- 
set,  623. 

Operation  of  Planetary  Gearing,  435. 

Operation  of  Selective  Sliding  Gear- 
set,  623. 

Operation    of    Sliding    Gearsets,    444. 

Operation  of  Three-Port  Two-Cycle 
Engine,  110. 

Operation  of  Two-Port  Two-Cycle  En- 
gines, 106. 

Operation  of  Valves,  150. 

Oscillating   Wristpin   Design,    190. 

Outer  Casing,  How  to  Remove,  547. 

Outer  Casing,  Loosening  from  Rim, 
547. 


Overheating  Caused  by  Rich  Mixture, 
650. 


Packing  Small   Spare  Parts,  606. 
Parts  of  Automobile  Power  Transmis- 
sion System,  408. 
Parts  of  Dry  Battery,  310. 
Parts  of  Ignition  Magneto,  348. 
Parts  of  Pressed  Steel  Frames,  463. 
Parts  of  Simple  Electric  Cell,  309. 
Parts  of  Simple  Ignition  System,  327. 
Parts  of  Spark  Plugs,   332. 
Parts  of  Two-Cycle  Engines,  106. 
Peerless  Carburetor  Construction,  276. 
Peerless  Cars,   Gear  Shifting  Method, 

624. 

Petroleum  Distillates,  232. 
Peugeot  Rear  Axle,  499. 
Pierce- Arrow  Cars,  Control  System  of, 

623. 

Pierce  Carburetor  Construction,  273. 
Pinching  Inner  Tubes,  558. 
Pi&on,    Construction    of    Differential 

Type,  111. 
Piston,    Design    of    Differential    Type, 

187. 

Piston,  Functions  of,  79. 
Piston  Rings,  Concentric,  191. 
Piston  Rings,  Construction  of,  190. 
Piston  Rings,  Eccentric,  191. 
Piston  Rings,  Functions  of,  190. 
Piston  Rings,  Methods  of  Joining,  191. 
Piston  Speed,  Definition  of,  129. 
Piston  Speed,   Safe  Limit  of,   129. 
Piston,  Two-Cycle,  186. 
Piston,   Two-Diameter,   187. 
Piston  Valves,   Hewitt,   173. 
Pistons,  Construction  of,   186. 
Planetary  Change  Speed  Gear,  Control 

of,  616. 
Planetary    Gearing,    Advantages    of. 

439. 


686 


Index 


Planetary  Gearing,  All  Spur  Type, 
437. 

Planetary  Gearing,  Operation  of,  435. 

Planetary  Gearsets,  Cause  of  Noisy 
Action,  650. 

Planetary  Gearsets,  Clutches  for,  428. 

Planetary  Gearsets,  Defects  of,  656. 

Plug  Gaps  for  Magneto  Current,  366. 

Plunger  for  Wristpin  Retention,   190. 

Plunger  Pump,  Oil,  377. 

Plungers,  Valve  Operating,  150. 

Pneumatic  Tire  Action,  519. 

Pneumatic    Tire    Construction,    519. 

Pneumatic  Tires,  Air  yalve  for,  522. 

Pneumatic  Tires,  Anti-Skid  Treads, 
525. 

Pneumatic  Tires,  Bolted-on  Type, 
524. 

Pneumatic  Tires,  Clincher  Type,  523. 

Pneumatic  Tires,  Dunlop  Type,  523. 

Pneumatic  Tires,  Inner  Tube  Construc- 
tion, 519. 

Pneumatic  Tires,  Methods  of  Casing 
Retention,  5224 

Pneumatic  Tires,  Non-Skid  Chains  for, 
528. 

Pneumatic  Tires,  Outer  Casings,  519. 

Pneumatic   Tires,  Protectors  for,   528. 

Pneumatic  Tires,  Quick  Detachable, 
522. 

Pneumatic  Tires,  Repair  of,  554. 

Pneumatic  Tires,  Rims  for,  522. 

Pneumatic  Tires,  Troubles  of,  552. 

Poor  Carburetor  Adjustment,  Symp- 
toms of,  648. 

Poor  Compression,  Causes  of,  644. 

Poor  Washing  Soaps,  Effects  on  Var- 
nish, 662. 

Porcelain   Insulated   Plug,  332. 

Portable  Vulcanizers,  Utility  of,  555. 

Power  Needed  to  Overcome  Air  Resist- 
ance, 64. 

Power  Needed  to  Propel  Car,  Deter- 
mination of>  68, 


Power  Plant,  Features  of  Unit  Con- 
struction, 114. 

Power  Plant,  Four  Point  Support, 
115. 

Power   Plant  Installation,   113. 

Power  Plant  Troubles,  Location  of, 
641. 

Power  Stroke,  Definition  of,  82. 

Power  Transmission  by  Bevel  and 
Spur  Gearing,  499. 

Power  Transmission  by  Bevel  Gearing, 
493. 

Power  Transmission  by  Shafts,  484. 

Power  Transmission  by  Side  Chains, 
484. 

Power  Transmission  by  Worm  Gear- 
ing, 493. 

Power  Transmission  Efficiency,  406. 

Power  Transmission,  Single  Chain,  484. 

Power  Transmission  Systems,  484. 

Preparations  for  Removing  Oil  Spots, 
639. 

Preparations  for  Treatment  of  Leather, 
664. 

Pressed   Steel    Frame,  463. 

Pressed  Steel  Frame  Parts,  463. 

Preservation   of  Upholstery,    665. 

Pressure  at  End  of  Compression 
Stroke,  81. 

Pressure  Feed  Oil  Systems;  384. 

Pressure  Feed  Systems,  244. 

Primary  Cell  Wiring  Methods,  311. 

Principles  of  Carburetion,  239. 

Principles  of  Dynamo  Action,  317. 

Principles  of  Engine  Starters,  561. 

Principles  of  Motor  Cars,  43. 

Principles  of  Two-Cycle  Engines,   105. 

Problem  of  Spring  Selection,  465. 

Producing  Acetylene  Gas,  570. 

Production  of  Electricity  by  Mechani- 
cal Means,  317. 

Progress  of  Automobile  Design,  39. 

Progressive  Sliding  Gearset,  444. 

Properties  of  Benzol,  333. 


Index 


687 


Proportions  of  Air  and  Gas  Mixtures, 

240. 

Proportions  of  Valves,  146. 
Protection  Casing  for  Driving  Chains, 

497. 

Protectors,  Disadvantages  of,  528. 
Protectors   for  Tires,  528. 
Pump,     Gear     for     Circulating     Oil, 

377. 

Pump,  Plunger  Type  for  Oil,  377. 
Pump  Supply  System,  246. 
Punctures,   Repair  of,  554. 
Purpose  of  Differential  Gear,  490. 


Qualities  Desired  of  Lubricants,  370. 


R 


Rack  and  Pinion  Steering  Gears,  475. 
Radiator    Compounds,    Anti-Freezing, 

634. 

Radiator  Protection  by  Shield,  638. 
Radiator  Solutions,  Calcium-Chloride, 

634. 

Radiator  Solutions,  Oil,  637. 
Ratio  of  Bore  and  Stroke,  126. 
Rayner  Two-Cycle  Motor,  223. 
Rear  Axle  and  Change  Speed  Gearing, 

457,  459. 

Rear  Axle,  Combination  Type,  490. 
Rear  Axle,  Floating  Type,  487. 
Rear  Axle  Forms,  487. 
Rear  Axle,  Peugeot,  499. 
Rear   Axle,   Torbensen,   497. 
Rear  Axle  Transmission,  Conventional, 

459. 

Rear   Axles,    "  Dead "   Type,    487. 
Rear  Axles  "  Live  "  Types,  487. 
Rear    Axles    wth    Double    Reduction 

Gears,  496. 


Rear  End  Suspension,  469. 
Reason   for  Cooling  Systems,   388. 
Reason  for  Lubrication  of  Mechanism, 

368. 

Reasons  for  Spark  Advance,  611. 
Regulation    of    Gas    Mixture    Supply, 

262. 

Regulation  of  Motor  Speed,  610. 
Removal   of  Bolted-on  Casing,   547. 
Removing      Grease      from      Running 

Gears,  662. 

Removing   Outer   Casing,    547. 
Reo  Car,  Control  System  of,  628. 
Repairing  Punctures,  554. 
Repairing    Sagging    Frame    Members, 

660. 

Repair  Outfits  for  Automobiles,  592. 
Requirements   of   Carburetor,   241. 
Requirements  of  Clutches,  410. 
Requirements  of  Oiling  Devices,  374. 
Results  of  Knight  Motor  Trials,  104. 
Retaining  Magneto  on  Base,  361. 
Retarded  Spark,  Effect  of,  611. 
Retention  of  Leather  Cone  Clutches, 

416. 

Reynolds  Rotary  Valve  Motor,  166. 
Rich  Gas  Causes  Overheating,  650. 
Rims,  Clincher,  522. 
Rims,  Fisk,  524. 

Rims  for  Solid  Rubber  Tires,  537. 
Rims,  Demountable,  531. 
Rims,  Dunlop,  522. 
Rims,    Quick   Detachable,   522. 
Ring  for  Wristpin  Retention,  188. 
Ring  Valve  Operating  Means,  171. 
Ring  Valves,  Sphinx,  169. 
Rocker  Arm,  Valve  Operating,  150. 
Roller  Cam  Follower,  150. 
Rope  for  Motorists,  603. 
Rope  for  Motorists,  Utility  of,  603. 
Rotary  Valve,  Double  Cone,  167. 
Rotary  Valves,   Conical,    168. 
Rotary  Valves,  Disk,  166. 
Rotary  Valves,  Drum,  166. 


688 


Index 


Rotary  Valves,  Itala,  163. 

Rotary  Valves,  Mead,  166. 

Rotary  Valves,  Reynolds,  166. 

Rules  for  Manipulating  Spark  Lever, 

611. 
Rules  for  Obtaining  Best  Tire  Service, 

558. 

Rules  for  Tire  Inflation,  549. 
Rules  for  Tire  Selection,  549. 
Running  Gears,  Removing  Grease 

from,  662. 


S 


Safe  Piston  Speed,  129. 

Sagging  Frame  Members,  Strengthen- 
ing, 660. 

Sand  Blister,  Cause  of,  554. 

Saurer   Economy   Carburetor,   282. 

Schebler  Model  "  E  "  Vaporizer,  265. 

Screw  and  Nut  Steering  Gear,  477. 

Scroll  Elliptic  Springs,  468. 

Secondary  Distributor  Action,  324. 

Sectional  Cushion  Tire,  536. 

Selective  Sliding  Gearset,  446. 

Selective  Sliding  Gearset,  Advan- 
tages of,  447. 

Selective  Sliding  Gearset,  Operation 
of,  623. 

Self-Starters  for  Gasoline  Engines,  561. 

Semi-Elliptic    Springs,    467. 

Separable  Head  Cylinder  Construction, 
123. 

Sequence  of  Cycles,  Four-Cylinder,  88. 

Sequence  of  Cycles,  Single-Cylinder,  87. 

Sequence   of  Cycles,   Six-Cylinder,   90. 

Sequence  of  Cycles,  Three-Cylinder,  87. 

Sequence  of  Cycles,  Two-Cylinder,  87. 

Series  Connection  for  Cells,  312. 

Set  Screws  for  Wristpin  Retention, 
188. 

Shaft  Drive  from  Friction  Transmis- 
sion, 433. 


Shaft  Driving  Methods,  484. 

Shaft  Driving  Systems,  Care  of,  650. 

Shaft    for    Pump    and    Timer    Drive, 

198. 
Shapes    of    Connecting    Rod    Sections, 

196. 

Shield    for   Radiator    Protection,    638. 
Shock  Absorber,  Coil   Spring,  585. 
Shock     Absorbers,     Auxiliary     Spring 

Type,  586. 
Shock    Absorbers,    Cam    and    Spring 

Type,  586. 

Shock  Absorbers,  Forms  of,  585. 
Shock  Absorbers,  Friction  Type,  587. 
Shock  Absorbers,  Functions  of,  585. 
Shock   Absorbers,   Oil   Check,   587. 
Shock  Absorbers,  Rubber  Buffer,  585. 
Side  Chain  Drive  System,  484. 
Side  Chain  Drive  from  Friction  Trans- 
mission, 433. 

Side  Slipping,  Cause  of,  505. 
Side  Springs,  468. 
Sight  Feed   Lubricators,  375. 
Signals  and  Alarms,  588. 
Silent  Chain  Camshaft  Drive,  156. 
Silent  Chains,  Use  in  Gearset,  441. 
Simple  Battery,  Disadvantages  of,  313. 
Simple   Electric    Cell,  Action   of,   309. 
Simple    Ignition    System,    Action    of, 

328. 

Simple  Ignition  System  Parts,  327. 
Simple  Spray  Carburetor,   249. 
Simple  Storage  Cell,  Action  of,  314. 
Single  Chain  Drive,  484. 
Single-Cylinder  Motor,  Horizontal,  83. 
Single-Cylinder  Motor,  Vertical,  84. 
Single-Cylinder  Sequence  of  Cycles,  87. 
Six-Cylinder  Engine  Ignition  System. 

343. 

Six-Cylinder  Induction  Manifolds,  297. 
Six-Cylinder      Motor,      Sequence      of 

Cycles,  90. 
Sleeve  and  Piston  Valve  Combination. 

161. 


Index 


689 


Sleeve  Valves,  Knight,  99,  160. 
Slide  Valve  Motor,  Knight,  97. 
Sliding    Gearsets,     Design    of    Four- 
Speed  Type,  451. 
Sliding   Gearsets,   Number   of   Speeds 

Provided,   447. 
Sliding   Gearsets,    Operation    of,    444, 

G23. 

Sliding   Gearset,    Three-Speed   Select- 
ive, 451. 
Sliding  Gearset  without  Direct  Drive, 

449. 
Sliding  Gear  Transmissions,  Defects  of, 

G57. 

Slip  Covers  for  Upholstery,  665. 
Slipping  of  Friction  Disk,  Prevention 

of,   656. 

Small   Spare  Parts,   Packing,  600. 
Solid  Gasoline  as  Fuel,  238. 
Solid    Rubber   Tires,    Attachment    of, 

538. 
Solid     Rubber     Tires,     Dual     Forms, 

538. 

Solid  Tire  Action,   519. 
Spacing  Magneto  Distributor  Contacts, 

350. 

Spare  Parts  for  Repairing,   597. 
Spark  Advance,   Reasons  for,  611. 
Spark  Gap,  Function  of,  337. 
Spark  Lever  Position,  Effect  on  Fuel 

Economy,  612. 
Spark    Lever    Position    for    Varying 

Speeds,  612. 
Spark  Lever,  Rules  for  Manipulating, 

611. 

Spark  Plug  Design,  332. 
Spark  Plug,  Functions  of,  30. 
Spark  Plug  Parts,  332. 
Spark    Plug,   Waterproof   Connection, 

338. 

Spark    Plugs,    Air    Gap    for   Magneto 
.  Current,  366. 
Spark    Plugs,    Combined    with    Glass 

Insets,  338. 


Spark  Plugs,  Combined  with  Relief 
Cock,-  336. 

Spark  Plugs,  Defects,  646. 

Spark  Plugs,  for  Two- Spark  Ignition, 
339. 

Spark  Plugs,  Installation  of,  335. 

Spark  Plugs,  Two-Pole,  340. 

Speed  Measuring  Devices,  589. 

Speedometer,  Centrifugal  Type,  591. 

Speedometer  Forms,  589. 

Speedometer  Operating  Principles,  590. 

Sphinx  Ring  Valve  Motor,  169. 

Spinning  of  Clutch  Cones,  420. 

Spot  Removing  Preparations,   639. 

Spray  Nozzle  Forms,  260. 

Squeaking  Sounds,  Causes  of,  651. 

Spring  Attachment  to  Axles,  471. 

Spring  Attachment  to  Frames,  471. 

Spring  Selection,  Problem  of,  465. 

Spring  Shackles,  Functions  of,  468. 

Spring  Wheel  Forms,  515. 

Spring  Wheels,  Disadvantages  of,  517. 

Springs,  Alloy  Steel,  471. 

Springs,  Compound  Forms,  473. 

Springs,  Full  Elliptic,  467. 

Springs,  Helical  Coil,  473. 

Springs,  Influence  on  Traction  Resist- 
ance, 471. 

Springs,  Laminated  Leaf,  466. 

Springs,  Scroll- Elliptic,  468. 

Springs,  Semi-Elliptic,  467. 

Springs,  Side,  468. 

Springs,   Three-Quarter  Elliptic,  468. 

Stability,  Influence  of  Center  of  Grav- 
ity, 461. 

Stamped   Metal   Wheels,  512. 

Starters,  Air,  564. 

Starters  for  Automobile  Engines,  561. 

Starters,  Ignition,  563. 

Starters,   Mechanical,   562. 

Starting  Automobile  Power  Plant, 
607. 

Starting  Car  with  Selective  Gearing, 


690 


Index 


Starting    Crank,    Method    of    Using, 

608. 

Starting  Gasoline  Engine  by  Air,  564. 
Starting    Gasoline    Engine    on    Cold 

Morning,  637. 

Starting  Mult i- Cylinder  Engines,  608. 
Starting  System,  Cadillac,  568. 
Starting  System,  Chalmers,  566. 
Starting     System,     Janney-Steinmetz, 

565. 

Starting' System,  "Never  Miss,"  565. 
Starting  Systems,  Electrical,  567. 
Steam  Car,  Advantages  of,  37. 
Steel  Tubing,  Use  in  Frames,  462. 
Steering   Animal   Drawn   Conveyance, 

473. 

Steering  Connections,  Care  of,  659. 
Steering  Gear  Action,  475. 
Steering  Gears,  Adjustment  for  Wear, 

478. 

Steering  Gears  for  Automobiles,  475. 
Steering    Gears,    Hand    Wheel    Move- 
ment, 479. 

Steering  Gears,  Irreversible,  475. 
Steering  Gears,  Mounting  of  Control 

Levers,  481. 

Steering  Gears,  Rack  and  Pinion,  475. 
Steering  Gears,  Screw  and  Nut,  477. 
Steering   Gears,    Use  of    Ball   Thrust 

Bearings,  481. 
Steering    Gears,    Utility   of    Eccentric 

Bushings,  478. 
Steering    Gears,    Worm    and    Worm 

Gear,  475. 

Steering  Knuckles,  Elliot  Type,  483. 
Steering  Knuckles,  Mercedes,  483. 
Steering  Knuckles,  Utility  of,  475. 
Steering    Mechanism,    Back    Lash   in, 

661. 

Stone  Bruise  in  Tires,  553. 
Stopping  Car  with  Selective  Gearing, 
,  627. 

Storage  Battery  Action,  313. 
Storage  Battery   Construction,  314. 


Storage  Battery,  Current  Strength, 
316. 

Storage  Battery  for  Automobile  Work, 
315. 

Storage  Cell,  Action  of  Simple  Type, 
314. 

Storage   of  Liquid  Fuel,  244. 

Straight  Line  Shaft  Drive,  486. 

Stream  Line  Body  Design,  67. 

Strength  of  Valve  Springs,  158. 

Strength  of  Wire  Automobile  Wheels, 
513. 

Strokes,  Actual  Duration^of,  91. 

Stromberg  Double  Jet  Carburetor,  280. 

Suggestions   for   Oiling,   632. 

Summary  of  Valve  Operation 
Methods,  154. 

Supplies  for  Motor  Car  Maintenance, 
599. 

Supplies,  Method  of  Carrying,  603. 

Supplies,  Miscellaneous,  602. 

Supplying  Kerosene  by  Direct  Injec- 
tion, 291. 

Suspension  of  Frame,  465. 

Suspension    of    Front    End,    468. 

Suspension  of  Rear   End,  469. 

Symptoms  Denoting  Defective  Car- 
buretion,  648. 

Symptoms  of  Poor  Carburetor  Adjust- 
ment, 648. 


Test    for    Acid    in    Calcium    Chloride 

Solution,  635. 

Tests  for  Battery  Capacity,  645. 
Tests  of  Knight  Motor,  104. 
T  Head  Cylinder  Construction,  137. 
Theory  of  Cylinder  Cooling,  389. 
Theory  of  Induction  Coil  Action,  329. 
Theory  of  Lubrication,  370. 
Theory     of     Thermo-Syphon     Cooling 

System,  393. 
Thermo-Syphon  Cooling  Systems,  393. 


Index 


691 


Threaded  Plugs  for  Wristpin  Reten- 
tion, 188. 

Three  Bearing  Four-Cylinder  Crank- 
shafts, 203. 

Three-Cylinder  Motor,  Sequence  of 
Cycles,  88. 

Three-Plate  Clutch  Constniction,  421. 

Three-Plate   Clutch   with  Brake,   424. 

Three-Point  Support  Advantages,  114. 
-Three-Port  Two-Cycle  Engine  Opera- 
tion, 110. 

Three-Quarter  Elliptic  Springs,  468. 

Three-Quarter  Scroll  Elliptic  Springs, 
468. 

Three- Speed  Selective  Sliding  Gearset, 
451. 

Tie  Bar,  Functions  of,  475. 

Time  of  Ignition,  181. 

Timer  and  -Distributor  Forms,  321. 

Timer  and  Pump  Drive  Shaft,  198. 

Timer,  Four-Cylinder  Types,  324. 

Timer,  Touch  Contact,  323. 

Timer,  Wipe  Contact,  323. 

Timers,  Arrangements  of  Contacts,  326. 

Timers  or  Distributors,  Defects  of,  646. 

Timers,   One-Cylinder  Types,    322. 

Timers,  Speed  of  Rotation,  322. 

Tire   Failure,  Causes  of,  552. 

Tire  Inflation,  Importance  of,  551. 

Tire   Inflation   Methods,   552. 

Tire  Inflation,  Table  of  Pressures,  551. 

Tire  Manipulation  Hints,  545. 

Tire  Irons,  Forms  of,  542. 

Tire  Irons,  Use  of,  542. 

Tire   Protectors,   528. 

Tire  Repair  Outfit,  545. 

Tire  Restoration,  Supplies  for,  540. 

Tire  Restoration,  Tools  for,  540. 

Tire  Size,  Table  for  Selection,  550. 

Tire  Sizes  and  Axle  Loads,  550. 

Tires  for  Automobiles,  517. 

Tool   Roll  and  Tool  Assortment,  592. 

Tools  and  Miscellaneous  Equipment, 
592. 


Tools  for  Mechanically  Fastened  Tires, 
547. 

Tools,    Use    and    Care    of,    594. 

Torbensen  Rear  Axle,  497. 

Traction  Resistance,  Influence  of 
Springs,  471. 

Transforming  Reciprocating  to  Rotary 
Motion,  89. 

Transmission  of  Power,  484. 

Treads,  Anti-Skid,  525. 

Treads,  Raised  Type,  525. 

Treating  Leather  Tops,  664. 

Trend  of  Construction,  40. 

Troubles  in   Carburetors,  648. 

Tubular  Front  Axle,  481. 

Tungsten  Filament  Bulbs,  577. 

Tungsten  Filament,  Current  Consump- 
tion of,  577. 

Two  Bearing  Four-Cylinder  Crank- 
shaft, 203. 

Two-Cycle  Cylinder  Ports,  Function 
of,  108. 

Two-Cycle  Engine,  Differential  Piston 
Type,  111. 

Two-Cycle  Engine  Disadvantages,  112. 

Two-C;pde  Engine  Parts,  106. 

Two-Cycle  Engine  Principles,  luo. 

Two-Cycle  Motor,  Air  Cooled,  402. 

Two-Cycle  Motor,  Amplex,  218. 

Two-Cycle  Motor,  Cote,  220. 

Two-Cycle  Motor,  Legros,  220. 

Two-Cycle  Motor,  Rayner,  223. 

Two-Cycle  Piston,  186. 

Two-Cylinder  Motor,  Sequence  of 
Cycles,  87. 

Two-Cylinder  Opposed  Motor  Features, 
93. 

Two-Diameter   Piston,    187. 

Two-Pole  Spark  Plug,  340. 

Two-Port  Two-Cycle  Engine  Opera- 
tion, 106. 

Two-Spark  Ignition  System,  339. 

Two-Throw  Crankshaft,  202. 

Types  of  Change  Speed  Gearing,  430. 


692 


Index 


Types  of  Cooling  Systems,  389. 
Types  of  Crankshafts,  199. 
Types  of  Lubricators,  374. 
Types  of  Valve  Plungers,  150. 
Typical    Engine    Stoppage    Analyzed, 

642. 
Typical     Four-Cycle     Power     Plants, 

225. 

Typical  Front  Wheel  Brakes,  506. 
Typical  Induction  Coil,  329. 
Typical  Magneto  Forms,  359. 
Typical    Motor    Control    System,    609. 
Typical  Valve  Timing  Diagrams,  182. 


U 


Underslung  Frame  Advantages,  461. 

Underslung  Frames,  461. 

Unit  Power  Plant  Features,  113. 

Upholstery,    Preservation    of,   665. 

Upswept  Frame  Type,  464. 

Use  and  Care  of  Tools,  594. 

Use   of  Combined   Clutch   and   Brake 

Pedal,  629. 

Use  of  Cone  Brake,  420. 
Utility  of  Auxiliary  Exhaust   Valve, 

399. 
Utility    of     Change     Speed    Gearing, 

429. 

Utility  of  Cut-Out  Valve,  305. 
Utility  of  Eccentric  Bushings,  478. 
Utility  of  Friction  Pedal,  6l6. 
Utility  of  Gas  Engine  Valves,  80. 
Utility  of  Gasoline  Strainers,  286. 
Utility  of  Motor  Car  Brakes,  499. 
Utility  of  Windshields,  584. 


Valve,   Bevel    Seat,   146. 
Valve,  Cast-Iron  Head,  147. 
Valve  Construction,  146. 


Valve  Design,  145.' 

Valve,  Electrically  Welded,  147. 

Valve,  Flat  Seat,  146. 

Valve  for  Pneumatic  Tires,  522. 

Valve  Head  Construction,  147. 

Valve  in  the  Head  Construction,  137. 

Valveless  Miesse  Engine,  161. 

Valve  Lifting  Cams,  149. 

Valve  Location  Features,  136. 

Valve,  One  Piece  Steel,  147. 

Valve  Operation  by  Plunger,  150. 

Valve  Operation  by  Rocker  Arm,  150. 

Valve  Operation,  Hydraulic,  151. 

Valve    Operation,    Indirect,    151. 

Valve  Operation  Methods,  150. 

Valve  Operation,  Methods  Summar- 
ized, 154. 

Valve  Placing  Methods,   137. 

Valve    Plunger   Types,    150. 

Valve  Proportions,  146. 

Valve  Springs,  Strength  of,  158. 

Valve  Timing,  Closing  Inlet,  180. 

Valve  Timing,  Exhaust  Closing,  178. 

Valve  Timing,  Exhaust  Valve  Lead, 
178. 

Valve  Timing  Instructions,  176. 

Valve  Timing,  Marking  Flywheel,  183. 

Valve  Timing,  Opening  Inlet,  179. 

Valve  Timing,  Steps  in,  185. 

Valve  Timing,  Typical  Diagrams,  182. 

Valves,  Concentric  Construction,  143. 

Valves,  Darracq  Rotary  Distributor, 
173. 

Valves,  Piston,  161,  173. 

Valves,  Rotary,  163,  166,  167. 

Valves  Sleeve,  160,  161. 

Valves  Split  Ring,  169. 

Valves,  Utility  of,  80. 

Vaporizing  Gasoline,  Early  Methods, 
247. 

Varnish  Deterioration  Because  of  Poor 
Washing  Soap,  662. 

Varnish  Deterioration,  Effect  of  Am- 
monia Fumes,  663. 


Index 


693 


Venturi  Tube  Action,  257. 
Vertical  Single-Cylinder  Motor,  84. 
Vibrator  Coil  Defects,  647. 
Voltage,   Definition   of,   312. 
Voltage  Required  for  Ignition,  316. 
Vulcanizers,  Acid  Cure,  545. 
Vulcanizers,  Electrical,  556. 
Vulcanizers,  Method  of  Using,  556. 
Vulcanizer,   Vapor,  556. 
Vulcanizing,  Temperatures  for,  556. 


W 


Wagon  Brake  Form,  499. 
Water  Circulating  Pumps,  392. 
Water    Circulation,    Impediments    to, 

650. 

Water-Cooled  Mufflers,  303. 
Water  Cooling  by  Forced  Circulation, 

389. 
Water  Cooling  by  Natural  Circulation, 

389. 

Water   Cooling   Methods,    389. 
Waterproof    Spark    Plug    Connection, 

338. 

Watt,  Definition  of,  312. 
Wick  Carburetor  Action,  247. 
Wick  Carburetor,  Lanchester,  251. 
Windshields,  Construction  of,  585. 
Windshields,  Glass,  585. 
Windshields,    Leather    and    Celluloid, 

584. 

Windshields,  Utility  of,  584. 
Winter  Care   of  Automobiles,  634. 
Winter   Care   of   Lubricating  System, 

637. 

Wire  Automobile  Wheels,  509. 
Wire  Automobile  Wheels,  Strength  of, 

513. 


Wire  for  Magneto  Ignition  Systems. 
366. 

Wire   Wheels,  Disadvantages  of,   513. 

Wiring,  Defects  of,  647. 

Wiring  Diagram,  Four-Cylinder 
Double  System,  365. 

Wiring  Diagram  of  Low  Tension  Sys- 
tem, 345. 

Wiring  of  Battery  Ignition  Systems, 
342. 

Wiring  Systems,  High  Tension  Mag- 
neto, 352. 

Wiring  System,  Transformer  Coil 
Magneto,  354. 

Wood  Automobile  Wheels,  509. 

Wooden  Wheels,  Artillery  Hub,  509. 

Wooden  Wheels,  Sarven  Hub,  509. 

Wood  Frames,  462. 

Worm  and  Worm  Gear  Steering,  475. 

WTorm  Gear  Driving,  493. 

Worm  Gearing,  Advantages  of,  495. 

Worm   Gearing,    Efficiency    of,   495. 

Wristpin,  Functions   of,   188. 

Wristpin   Retention   by   Plunger,   190. 

Wristpil  Retention  by  Ring,   188. 

Wristpin  Retention  by  Set  Screw,  188. 

Wristpin  Retention  by  Threaded 
Plugs,  188. 

Wristpin,  Retention  of,  188. 


Yearly  Output  of  Automobiles,  35. 


Zenith  Double  Jet  Carburetor,  284. 


STAMPED  BELOW 


AN  INITIAL  FINE  OF  25  CENTS 

WILL  BE  ASSESSED  FOR  FAILURE  TO  RETURN 
THIS  BOOK  ON  THE  DATE  DUE.  THE  PENALTY 
WILL  INCREASE  TO  SO  CENTS  ON  THE  FOURTH 
DAY  AND  TO  $1.OO  ON  THE  SEVENTH  DAY 
OVERDUE. 


APR  30  1941  M 

OCT  28 

la44 

"Vcr, 


WlBl 

1 

1 

* 

IAY    9  1987 


LD  21-100m-7,'40 (6936s) 


'U.C. 


BERKELEY  LIBRARIES 


YC   1939" 


i 


r 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


